Abstract: In order to improve the calibration accuracy of the torque sensor calibrator, a calculation model for the friction torque of the deep groove ball bearing used in the calibrator was established, and the error generated by the bearing friction torque was compensated in the host computer program.By contrast, the influence of different bearing structure parameters on the friction torque is studied.The results show that the measurement accuracy of the bearing calibrator is significantly improved after friction torque compensation.The friction torque of the bearing increases with the increase of the number of steel balls, decreases with the decrease of the curvature radius coefficient of the inner and outer grooves, and decreases with the increase of the bearing radial clearance.The research results propose a method to improve the calibration accuracy of the torque sensor calibrator, and provide a theoretical basis for the low-friction optimization design of deep groove ball bearings.