The Rotary steering drilling technology provides an effective technical means for the development of high angle and horizontal wells. The precision control of steering force determines whether the real drilling trajectory is in the design trajectory. In order to obtain more precise steering force,aim at the uncertainty and difference of the damping components in hydraulic actuators, this paper designs a steering force testing calibration system, the system can measure simultaneously three way hydraulic thrust, reducing the coupling effect of three thrust and improve the measurement accuracy, and developing PC software which can provide realtime thrust curve display, data processing automatically, calibration parameters generating automatically, test report saving automatically and etc, greatly improving the work efficiency. Ensure the accuracy of drilling trajectory control and prevent drilling accidents.