Cultivation method for improving content of ursolic acid in leaves of eriobotrya japonica

The invention discloses a cultivation method for improving the content of ursolic acid in leaves of eriobotrya japonica. The method comprises the following steps: an eriobotrya japonica tree with robust growth and without disease or pests in a full bearing period is selected; covering is performed by using a sunshade net after flowers are withered or an early stage of young fruits; the whole treeis covered by using two layers of the sunshade net, the sunshade net is black, and the shading rate is 85%-95%; the internal light transmittance is maintained at 2-15%; high performance liquid chromatography is used to measure the content of the ursolic acid in the leaves; leaves for measuring the ursolic acid content are old mature autumn shoot leaves located at the periphery of a tree crown, andthe leaves grow normally and have no disease specks; the best time for extracting the ursolic acid from the leaves is within 15-60 days; the sunshade nets are removed after 60 days, and the eriobotrya japonica tree recovers f