Inputting the velocity of moving target to the automatic tracking system of TV or infrared is an effective method to improve the tracking accuracy in electro-optical theodolite. In order to obtain the velocity of moving target, the methods of identifying the delay time of TV or infrared off-target and Kalman filter are designed. Fitting the TV or IR off-target for the code position of electro-optical theodolite and forecasting the velocity of being tracked target can compose compound control system. The simulation and test results show that velocity of moving target can be forecasted by fitting the target-missing quantity for instrument position quantity using the methods and tracking precision can be improved in servo-control system.