As slippage influences the tracking error of a telescope with friction drive, a way to detect and correct the slippage of friction drive was proposed for astronomical optical telescopes. A slippage dynamic detection system, a normal pressure active adjustment system, and a simulation and detection system of load fluctuation were established. The position of dynamic load was measured by a tape encoder and the position of active drive wheel was measured by a coaxial angle encoder. Then, the slippage was detected by transmission ratio. The Programming Multiple Axis Controller(PMAC) was used as a main control unit to control the normal pressure motor to adjust pressure and the control algorithm was also modified. By above way, enough friction drive force was obtained and the slippage was alleviated or eliminated. Experimental results indicate that the way can correct the slippage in time, improve the tracking precision of the optical astronomical telescopes and increase the stability of the drive system. In the most severe case, the friction drive system can resume the high accuracy tracking by detecting the slippage in 100 ms and completing the correction in 74.2 s. The method can be used for both single-point friction drive and multi-point friction drive and can solve the slippage caused by nonlinear disturbance.