The invention discloses a despin method after a space robot captures non-cooperative targets. The despin method includes the steps that 1, a kinetic equation after the space robot captures the non-cooperative targets is built; 2, a kinetic equation of space non-cooperative targets is built; 3, a kinetic model after the space robot captures the non-cooperative targets is built; 4, a PID control method is used for applying a joint control moment to a space-robot mechanical arm joint, the angular speed of the space-robot mechanical arm joint is zero, and despin is completed. A strategy is definite, a control method is simple, despin of the non-cooperative targets can be completed in a short time, and the method provides convenience for later operations. Under a condition that a joint brake exists, energy does not need to be provided in the whole process, and the energy is saved. The despin method has the high robustness, and is free of requirements for motion states of the non-cooperativetargets, and even if in the despin process, the space robot is interfered or the non-cooperative targets generate confrontations, the despin process can be still completed.