① Adjust the rational distribution of branches and leaves. That is, on the basis of reshaping, the density, distribution direction and leaf area coefficient of each part of the crown are adjusted to maximize the effective photosynthetic area of the crown.

② Regulating growth and fruiting. Make nutrition grow normally but not too much; Moderate flowering and fruiting without weakening the tree; At the same time, it can prevent fruit trees from aging ahead of time and renew and rejuvenate in time.

③ Adjust the proportion of branches. Short branches have short growth period, low consumption and early accumulation, but few leaves and low total photosynthesis; Vegetative branches have a long growth period and high consumption, but they also accumulate a lot in the later stage. Different tree species and tree ages need to have corresponding and appropriate branch proportions, so that the operation, distribution, consumption and accumulation of nutrients in a year's growth cycle can be coordinated according to the normal growth and reproduction rhythm. This can be achieved by pruning.

(4) Pruning can also balance the growth potential among the population plants and between the main branches of the plants, so as to achieve a balanced yield and facilitate management. In addition, pruning is also a means to coordinate the growth of shoot and root system.