Abstract: In view of the current problems in coal mine power network, such as low power factor, the line of high running current, reactive power loss and harmonic pollution and so on, this paper designs a kind of static var generator based on APF. The device adopts three level technologies and multiple technologies. It can achieve the function of active power filter. The device has been tested in the heading face and the mining area surface of Xin Mining Group of Shandong power. The test results show that the dynamic response time is better than that of 5ms. Its soft start technology ensures the power system without impact starting. Its modular and miniaturization design is easy to install and it can function by multiple parallel straight hanging grid.