To address the issue that most conceptual hydrological models considering snowmelt are lumped models, a gridded Xin’anjiang model considering snowmelt and rainfall-runoff processes (iRainSnowHydro model) was constructed based on the gridded Xin’anjiang model by coupling a snowmelt module. Daily runoff simulations were conducted taking the Liyuan basin in the upper reaches of the Jinsha River and the Wunonglong basin in the upper reaches of the Lancang River as typical basins, and the results were compared with those of a lumped snowmelt runoff model (Hydromad model). The results indicate that the iRainSnowHydro model exhibits good daily runoff simulation performance in both the Liyuan and Wunonglong basins, with R2 and NSE exceeding 0.85 and the absolute value of PBIAS being less than 10% in the calibration and validation periods. The simulation performance of the iRainSnowHydro model is superior to that of the Hydromad model, and its distributed structure has significant advantages.