The Thrust calibration plays an important role in thrust measurement, and its calibration accuracy directly affects the measurement result. The traditional calibration method has poor precision and low efficiency, which can not meet the current measurement requirements. In this paper, a new on-line thrust calibration device is proposed. The cylinder tensioning force is generated by the cylinder with servo motor. The closed-loop PID system is formed by the pressure control system，the tension piston system and the standard force sensing system. The precise control of the pulling force is realized, and the data acquisition system collection the calibrated value in the host computer to complete the final calculation.