Abstract: The technical challenge of simulating a zero-gravity environment for spacecraft module separation tests was investigated in this study. To address this challenge, a motor-controlled vertical separation test system was designed and developed. Through comprehensive control simulation, the force exerted by the system’s tension control device and the separation parameters were predicted. These predictions were then validated through actual spacecraft module separation tests. The test results show that the system effectively simulates a zero-gravity environment in the vertical direction during module separation, with a gravity offloading efficiency exceeding 95%. Additionally, it achieves controlled separation speeds, ensuring the safety of the separation process. Compared with existing methods, this test system has the advantages of low cost, simple operation, and strong versatility, offering reference for subsequent ground separation tests of various models.