Abstract: To solve the problem of frequency conversion speed governor of feed pump of pressure filter seriously disturbing grid voltage in Panyi coal preparation plant,using permanent magnet speed governor controlling pressure filter feed pump. The paper described the structure,working principles,characteristics and technical parameters of the governor,and compared and analyzed the speed adjustment effects of permanent magnet speed governor and frequency conversion speed governor. Practical results show that,the permanent magnet speed governor was used in pressure filter feed pump is entirely feasible,and compared with the frequency conversion speed governor,it has the features of energy saving,reliable operation,low electromagnetic interference,long life,low starting current,good vibration isolation effect,well adaptability.