The widespread use of converters，inverters and other nonlinear elements in mine power supply system leads to power harmonic problems becoming increasingly prominent. Active power filter can compensate various frequency harmonics effectively，also make grid electricity quality better．The specialty in power supply system asks high demand of the stability and dynamics of active power filter. To the above-mentioned question，this paper presented a method that uses improved repetitive control in parallel with PI control to enhance control effect．The accuracy of repetitive controller is implemented by introducing deadbeat control，which has specialty of advanced calculation．The simulation results verified the feasibility of this control strategy．