Abstract: Accurate prediction of on-orbit maintenance time and timely delivery of maintenance support resources are of great significance for improving the reliability of the space station. In view of the limitations of existing on-orbit maintenance time prediction methods and the impact of microgravity on maintenance time, a method for correction of predicting maintenance time of on-orbit repairable systems was proposed based on the simulated microgravity experiment. By using a neutral buoyancy water tank to simulate the microgravity environment, a disassembly task was carried out underwater and the time was recorded to obtain the reference action time of each joint. The accuracy of the method was verified by comparison with the MOD method. Then, taking account of other influencing factors in the space station, the reference action time standard of the space station on-orbit maintanance was derived based on the data of the simulated experiments. The results may provide a reference for the prediction of maintenance activity time and the maintenance-oriented design of the space station.ion.