In this study, the physicochemical properties of beef paste and the solubility, structure, aggregation state, and rheological properties of myofibrillar protein were compared before and after Volvariella volvacea (Vv) powder (5%, m/m) treatment, in order to analyze the mechanism of straw mushroom on beef paste quality. The results showed that Vv effectively reduced the cooking loss rate of beef paste, but increased the pH value and volatile base nitrogen content of meat, and darkened the color of meat. Among them, the cooking loss of beef paste samples was the lowest (3.44%) after 48 h of treatment, which was 4.48 times lower than that of the control group. At the same time, with the extension of treatment time, protein solubility decreased first and then increased, the degree of carbonylation and conversion of sulfhydryl group to disulfide bond gradually increased, and the content of α-helix gradually unwound from 34.50% to 29.50%. After treatment, the degree of protein degradation and aggregation was increased, and the gel rheology was significantly improved. These results indicate that the endogenous components of Vv may affect the flavor and texture of meat products by promoting protein oxidation and hydrolysis. The above research results are helpful to analyze the influence mechanism of edible fungi on the quality of meat products, and provide theoretical basis for the application of Vv in the development of new flavor meat products.