The pit field is a rectangular or square pit with a depth of 6-7m and a length of L2-15m, and then a 10- 14 cave is dug on the four walls of the pit, with a quantity of about 2,000 cubic meters of earthwork. The cave is about 3m high, 8-12m deep and 4m wide. The cave walls below 2 meters are vertical, and those above 2 meters are arched roofs. One of the holes was cut into a slope to form a stepped tunnel leading to the ground at an oblique right angle. It is the passage for people to travel, called doorway, and the entrance to the pit. There are three kinds of entrances to pits: straight, curved and rotary. Most caves have only one door (also called locking the door), and some have two doors, called Gate 1 and Gate 2 respectively. In the past, women's activities were limited to the inside of the gate and the outside of the second gate. Dig a rotary kiln at one side of the gate kiln, then dig a well with a depth of 20 to 30 meters and a diameter of 1 meter, and add a shaft drum to solve the draught problem of people and animals.

This kind of village composed of pits is not limited by topography, and can be arranged in rows, rows or scattered as long as a certain distance is kept between households. There are no houses on the ground in this village. Walking into the village, you can see that every household is hiding underground, which constitutes the most unique underground village on the Loess Plateau.

Pit yards are generally single-door caves, and there are also two yards and three yards, that is, a doorway is connected with two or three pit yards. As far as the shape of the pit is concerned, there are only two kinds: square and rectangle. According to its gossip orientation, it can be divided into two categories: dynamic houses, also known as Dongsi houses, including earthquake houses with the east as the top, single-family houses with the south as the main, Kanzhai houses with the north as the main and Xunzhai houses with the southeast as the main. Most of these patios are rectangular, with a length of 14- 18m and a width of 10- 12m and 8-l2 holes. Static houses, also known as West Four Houses, include exchange houses dominated by the west, dry houses dominated by the northwest, Kun houses dominated by the southwest and Gen houses dominated by the northeast. Most of these patio kilns are square, with a side length of about 12- 16 meters and a depth of about 7 meters, with 10 holes.

Around the pit yard and the ground, build a circle of blue brick eaves for rainwater drainage. Build a fence (also called parapet) 30-50 cm high on the eaves, and plant some shrubs such as Zizyphus jujuba. This fence is also made around the door leading to the bottom of the pit. These low walls are designed to prevent rainwater from flooding into hospitals and protect people from working on the ground and children's safety. Third, architectural decoration is needed to make the whole pit look beautiful and harmonious.

Living in a pit, drainage and seepage prevention are the most important. Almost all the auxiliary facilities of pit foundation are from this perspective, and they are also the main part of the "treatment" (reinforcement and repair) of residents' every wedding activity. The kiln surface (the facade of the cave) is plastered with mud except the windows, and the base is generally reinforced with blue bricks. There is a circle of blue bricks around the ground in the yard. The center of the pit is about 2 meters narrower than the edge of the pit, and about 30 cm is dug downward, and a puddle (well) with a diameter of about 1 m is dug in its shady corner (generally in the southeast corner). The bottom of the pit (well) is covered with slag, which is mainly used for storing rainwater and draining sewage. In some places, these rainwater will be used for human and animal drinking after precipitation.

Each cave in the cellar is divided into main kiln, guest kiln, kitchen kiln, animal kiln, toilet, door kiln and other functions. The main kiln has three windows and one door, the highest, and other kilns have two windows and one door. There are no doors and windows in the latrine kiln and the doorway (because the door and the second door of the doorway kiln are made in the cave and cannot be seen outside). Most of the kiln doors in the cellar are double doors, mainly composed of Sophora japonica and Toona sinensis. The paint is mostly black paint with red lines, and there is a smoke tunnel with a pot cavity and a heatable adobe sleeping platform on one side of the door. The windows are square, covered with white paper or glass, and stick grilles is celebrated during festivals. Cave size, the general main kiln is the ninth five-year plan kiln, with a width of nine feet and a height of nine feet and five inches. Other kilns are 85 kilns, which are eight feet wide and eight feet five inches high. On the sunny side of the door is the main kiln where the elders live, and on the left and right are the side kilns.

In the traditional pit yard, adobe is often used to build kang in caves, and there are generally separate caves for kitchens, granaries, chicken houses and cowsheds. Cattle, sheep, chickens, dogs, etc. Can be kept in captivity in hospitals, where people and animals live. Small caves can also be dug in the cave, called rotary kiln, for storing sundries or connecting tunnels between caves. The ground on the top of the yard is used for threshing and drying grain. There is a small hole on the top of the cave where the grain is stored in the yard, which is called "horse eye". In the harvest season, the dried grain can flow directly from the horse's eye into the grain depot placed in the house. The grain depot is made of reeds. Spread a layer of wheat bran with a thickness of about 20 cm under the warehouse, and cover it with a layer of wheat bran when the ears are full. Finally, the top of the warehouse is sealed with mud, and the grain can be stored for three to five years without insects and decay. There is also a "horse eye" at the top of the toilet, which can ventilate on the one hand and directly pour dry loess into the kiln on the other.

1-2 pear, elm, tung or pomegranate trees are generally planted on the ground in the middle of the pit yard, and the crown is higher than the ground, exposing the treetops. When I entered the village, I only heard people talking and laughing, chickens crowing and livestock crowing, but I couldn't see the houses in the village. "Seeing the tree but not seeing the village, not seeing the house in the village and not seeing people is its true portrayal. Some people call it the underground "Beijing Siheyuan".