Plastic pruning is an important measure to promote early fruiting and high yield of hazel trees, which can be divided into winter pruning and summer pruning. Pruning in winter should be carried out after defoliation and before branch germination in the following spring, preferably in February-March. The general principles of young tree pruning are: light pruning and appropriate short cutting, promoting branch expansion, increasing the number of branch groups, expanding crown and cultivating tree shape. ? At present, Corylus heterophylla mainly adopts a single trunk shape: the tree has a trunk with a height of 40-50 cm, and 3-4 main branches are staggered in different directions. Side branches are left on the main branches, and the growing side branches and fruiting line branches are attached to the side branches, forming a natural happy shape. The stems are short and the height of the trees is 3 ~ 4 m. After the first 1 year planting, the stems are fixed and the height is 50 ~ 60cm；. In the second year, 3-4 main branches in different directions are selected above the trunk, and each main branch is lightly sheared and short sheared, with the pruning belt length of 1/3, and the cutting mouth is full of external buds; In the third year, on each main branch, 2 ~ 3 lateral branches are selected for light cutting and short cutting. The extension branches of the main branches are also light and short, which makes them tend to grow upward and the inner branches cannot be cut; In the fourth year, the extension branches of the main lateral branches of each layer are shortened to expand the crown. ? At the young tree stage, the main lateral branches are light and short, and the branch length is truncated 1/3. Trees in full fruit period should be pruned according to the growth and development of hazelnut. Generally, the extension branch length of the main side branch is shortened to 1/3, and new branches are constantly produced. Except for diseased branches, diseased branches and extremely weak branches, branches with cavities are not pruned, and fruiting mother branches are cultivated, and moderate branches and short branches are not pruned. ? Summer pruning: May-July, from germination to defoliation. It is mainly to pick the heart, pull out the branches and remove the sprouting. Kerning can regulate vegetative growth, promote lignification, control excessive growth of branches and promote the formation of more flower buds. Branching is mainly to increase canopy illumination and promote the formation of more flower buds. Except the sprouting tillers, all the sprouting tillers under the tree are removed to reduce the nutrient consumption of the tree.