As its high safety, flexible operation and many other advantages, tethered space robot (TSR) will be widely applied in the future on-orbit service. Stable release is one of the key technologies of TSR. In this paper, the release dynamic model is established; the release dynamic character of TSR is analyzed; the intelligent control system is deigned by using CMAC neural networks. Take the tangential direction for example, the instable release is simulated. Simulation results show that: the intelligent control system can complete the stable release task very well. The control system has a less sensitiveness for measurement error and tether interference. The control system is robust and the control precision is very high.