The variable-speed constant-frequency (VSCF) wind generator is the main trend type of current wind generators. And as one part of the core components of VSCF wind generator control system, the pitch system can effectively ensure the safety, stability and efficient operation of the wind generator. In the paper, the principles and the two kinds of actuators of pitch control were briefly introduced, and the basic structures of electric drive pitch system were analyzed significantly. Besides, the applications of dc servo motor and ac servo motor in electric pitch system were also analyzed. Through comparing the respective advantages and disadvantages of dc servo and ac servo systems, it is concluded that the ac servo system has greater advantages than the dc servo system combined with the increasing single wind generator capacity.