Stepper motors are widely used in space optical remote sensing mechanisms. The driving circuit and the motor in traditional design correspond in quantity, in order to achieve the drive control of large-scale stepper motors, a large number of relays are required for signal switching. The design has the problem of excessive circuit scale and high cost. In addition, remote sensing mechanisms often need to be locked during the launch process, which is generally achieved through the holding torque of stepper motors. However, a large number of stepper motors are simultaneously powered, which can also lead to high power consumption in the camera subsystem. In order to realize the drive control and weak current locking function of large-scale stepper motors, this paper studies the drive multiplexing technology of multi-channel spaceborne stepper motor. The designed drive multiplexing circuit can realize time-sharing motion control and synchronous locking function for multi-channel stepper motors, and the locking current can be adjusted according to actual needs. For the designed drive multiplexing circuit, 10 stepper motors are selected for functional testing. The experimental results show that 10 motors can achieve time-sharing motion control function, and the power supply current is 3 A, which is the rated current value of the stepper motor. The 10 motors can achieve synchronous locking function and the power supply current during locking is 5 A at the modulation frequency of 100 kHz, while the average locking current of a single motor is 0.5 A, only 1/6 of the traditional single-phase locking current. Based on multi-channel spaceborne stepper motor drive multiplexing technology, not only can the motion of large-scale stepper motors be controlled, but also synchronous weak current locking function can be achieved, effectively reducing the power consumption of the system and improving the reliability of optical remote sensing launch process and in orbit operation.