The invention discloses a rosa sterilis var. leioclada orchard soil compound improver and a soil improvement method. A winter fertilization soil improvement method is employed. Specifically, the formula of the compound improver comprises: 800-1200 parts of rosa sterilis var. leioclada branches, 80-100 parts of cantharellus cibarius liquid strain, 10-20 parts of sucrose, 0.5-0.8 part of diammoniumhydrogen phosphate, 0.05-0.08 part of cellulase, 0.06-0.08 part of amylase, 0.08-0.1 part of calcium bicarbonate, and 0.03-0.05 part of carbendazim. The rosa sterilis var. leioclada orchard soil compound improver and the improvement method provided by the invention are simple in operation, increase the activity of soil microorganisms, improve the soil porosity and breathability, increase the rootsystem absorption area, improve the resistance, use less or even no pesticide and fertilizer, at the same time improve the soil structure, increase the quantity and quality of soil aggregates, the yield is high, and the cost is low, the heavy metal content of the product decreases, the product safety is greatly improved, and industrialization development of rosa sterilis var. leioclada planting can be realized.