The pruning of perennial flowers is mainly plant type management. By adjusting plant density, cutting off diseased leaves, thinning out redundant flowers and leaves, thinning out dead roots and other measures, the above-ground and underground growth and development are promoted, and good ornamental effects are achieved. Because perennial flowers are mostly clustered, with basal leaves and terminal inflorescences, the ornamental effect is mainly clustered, which not only shows the overall richness, but also shows the difference of relatively independent effect with small areas. Therefore, plastic pruning should not only consider the whole, but also the role of small groups, which is different from the management measures of annual flowers. More work should be done in density adjustment, plant cluster control and thinning residual branches and leaves. Some species are suitable for enucleation or pruning to promote lateral branches, which should be completed before flower bud differentiation. In addition to pruning on the ground, underground roots should also be pruned, thinned and cut off to promote root regeneration and rejuvenation.