When the central main branch of the young tree reaches a certain height, it should be pruned as needed, and 4 ~ 5 strong branches should be left for main branch culture, so that it can be dispersed up and down. Cut off the top of the main branch and leave a bud or lateral bud under the incision. If the angle between the main branch and the trunk is small, buds will remain, and vice versa. Too dense lateral branches can be sparse as soon as possible. When the main branch is elongated to a certain extent and the interval is large, it is advisable to keep strong branches for lateral branch culture, so that both the main branch and the lateral branch can receive sufficient sunlight. Gradually prune the supporting branches left before the central main branch. Cut off useless branches, long branches, buds, etc. Any time. After defoliation in autumn or before germination in early spring, pruning and shaping should be properly carried out every year, and dead branches, over-dense branches and long branches should be thinned to make the branches evenly distributed, so that they can grow vigorously and bloom luxuriantly in the coming year. Perennial trees need pruning, regeneration and rejuvenation.