One of the most popular edible mushrooms in the world,Flammulina velutipes, has been shown to possess pharmacological properties such as anti-inflammatory and antioxidant properties. However, the potential activity of the brown strain ofF. velutipes, a hybrid between the white and yellow strains, has not been thoroughly investigated. Numerous studies have been conducted in recent years to determine whether natural products can aid in improving or treating kidney diseases. In this study, we focused on the renoprotective effects of the brown strain ofF. velutipeson cisplatin-induced acute kidney injury (AKI) in mice. Mice were pretreated with water extract from the brown strain ofF. velutipes(WFV) from day 1 to day 10, with a single-dose intraperitoneal injection of cisplatin on day 7 to induce AKI. Our results demonstrated that WFV administration resulted in a reduction in weight loss and the amelioration of renal function and renal histological changes in mice with cisplatin-induced AKI. WFV improved antioxidative stress and anti-inflammatory capacity by increasing antioxidant enzymes and decreasing inflammatory factors. The expression of related proteins was determined via Western blot analysis, which showed that WFV could improve the expression of apoptosis and autophagy. We used the PI3K inhibitor Wortmannin and found that WFV achieved a protective effect by modulating the PI3K/AKT pathway and the expression of autophagy. Overall, WFV as a natural substance could be used as a new therapeutic agent for AKI.