To explore the temperature distribution of the friction pair on hydroviscous drive during the pure fluid stage,the thermalfluidsolid coupling model of the friction pair was established,numerical simulation of the friction pair with radial groove was carried out by using fluid simulation software FLUENT,and the nephograms of temperature distribution of the friction pair were obtained.The temperature data of oil film between friction pairs in radial oil groove were measured by setting up the testbed of hydroviscous drive device.The results show that,in the radial direction,with the increase of radius,the temperature of friction pair is increased gradually,and the temperature in the area with groove is lower than that of the area without groove. In the circumferential direction,the temperature in the area with groove is higher than that of the area without groove at the same radius,which indicates the groove can effectively reduce the working oil temperature.The temperature rise of friction disk in the pure oil film stage is obviously higher than that of dual friction disk.The trend of numerical simulation and experimental results is basically consistent, which verifies the reliability of theoretical analysis.