1. Bulldozer Bulldozer is a main type of earth-moving machinery, which can be divided into crawler type and tire type according to the walking mode, because there are few tire bulldozers. This paper mainly introduces the structure and working principle of crawler bulldozer. The basic operations of bulldozer excavation are: a. shoveling soil; B. break ground; C. unloading soil. 2. Scraper Scraper is a kind of machinery that can comprehensively complete digging, moving, unloading, filling and leveling. According to the different walking mechanisms, it can be divided into traction scraper and self-propelled scraper. According to the different operating systems of LHD, it can be divided into hydraulic LHD and cable LHD. The scraper is flexible in operation, not limited by terrain, without special roads and high in production efficiency. 3. Loader Loader is a kind of earth-moving machinery widely used in highway, railway, construction, hydropower, port, mine and other construction projects. Mainly used for shoveling earth, sand, lime, coal and other bulk materials. , and can also be used for light shovel operation of ore and hard soil. Replacing different auxiliary working devices can also be used for bulldozing, lifting and loading and unloading wood and other materials. In road construction, especially in high-grade highway construction, loaders are used for filling and excavation of subgrade engineering, aggregate and loading of asphalt mixture and cement concrete yard. In addition, it can also carry out operations such as bulldozing, leveling and towing other machinery. Loader has become one of the main types of earthwork construction in engineering construction because of its advantages of fast working speed, high efficiency, good maneuverability and easy operation.