Abstract: This paper studies the control of a dual-arm space robot system with bounded input torques to track a desired trajectory in the joint space, when the location of the base and the attitude are uncontrolled. Based on the Second Lagrange approach and the momentum conservation, a dynamics model of the dual-arm space robot system is built. Then, the saturated hyperbolic tangent function is adopted to design a new kind of control algorithms to control the driving torques of joints. Finally, the closed-loop error system is decomposed into a reduced-order model and a boundary-layer model based on the singular perturbation theory. The exponential stability of the state origin is proved by using the Lyapunov function. The numerical simulation results show the effectiveness and the superiority of the control algorithm.