Abstract: In the scheme of a space debris removal system with the space-based laser(SBL), a kJ-class high-power laser, with a high additional velocity, is to be used. However, the implementation of the kJ-class space-based laser systems is not feasible in the engineering pratice. In this paper, the onboard removal procedure based on the laser system of J-level energy is simulated, and the influential parameters are analyzed. The simulation results of the space-based laser system of 500 km in altitude show that the incremental velocity and the perigee decrease are of an accumulating nature during the removal procedure. Higher frequency and longer distant range of the laser can increase the effective acting time, with a lower perigee of the targeted debris. It is indicated that with the long-term engagement, the J-class low-power laser instead of the kJ-class high-power laser can also be used to drive and remove the middle-sized debris.