Observing practice teaching based on system theory and cybernetics,it is indubitable that practice teaching is a control system．Cybernetics considers that interfere information of environment can act on both the controlled and exert–controller．So,before the appearance of output information,exert –controller can sent out control information in advance to correct the deviation of system,instead of the deviation has already emerged．It is just feed-forward control．The paper surveys feed-forward control in practice teaching from system theory in order to emphasize the importance of feed-forward control in practice teaching．The implement way of feed-forward control in practice teaching system is put forward．