The work aims to study the effect of stearic acid modified polyvinyl alcohol film on fruit preservation. The solution casting method was adopted. Polyvinyl alcohol (PVA) film was modified with stearic acid as modifier, stearic acid-96 as emulsifier and polyethylene glycol-400 as plasticizer. Its structure was analyzed by FT-IR. The effects of stearic acid addition on the water resistance, tensile strength, elongation at break and appearance of the film were investigated. With prune as the preserved object, its respiration intensity, soluble solid content and weight loss rate were measured regularly, and the freshness of the prune was analyzed to evaluate the preservation effect of the modified film. Ester bond was formed between stearic acid and polyvinyl alcohol, and the water resistance of the film was improved obviously. When the content of stearic acid increased from 0% to 20%, the moisture permeability decreased from 294.42 g/(m2•h) to 75.99 g/(m2•h), which decreased by 74.19%. The solubility decreased from 26.85% to 12.90%. The tensile strength, elongation at break and transparency of the film decreased slightly. Compared with blank group and PVA film group, the stearic acid/PVA group delayed the respiratory climacteric peak of prune for 2 days, and decreased the weight loss rate of prune obviously. Stearic acid/PVA group extended the shelf life of prune by 3.3 days. Polyvinyl alcohol modified by stearic acid can enhance the water resistance, the packaging strength and the preservation effect of the film.