Aiming at facilitating the control of two servo motors in the tensiontorsion composite system, a host computer interface based on MFC was designed. Through the serial communication, the corresponding parameters of the servo driver were set by using different button operations to control the operation of two servo motors. The servo driver monitoring data were received by the host computer in real time to draw the speed, displacement and torque curves. For the case where the information frame was received incorrectly during data reception, the method of splicing two adjacent error information frames was used for repair. The results showed that the system function and the monitoring of motor operating conditions could be realized in the host computer interface.