Abstract: In view of problems of high cost and inconvenient installation by use of piezoelectric force sensor and impact force sensor to measure impact frequency, a low-frequency impact frequency measuring circuit with resistance strain force sensor was designed. According to working principle of resistance strain force sensor, the circuit firstly uses amplifying circuit to amplify output signal of the sensor, then uses voltage comparing circuit to generate square wave signal, and uses monostable trigger circuit to make shaping for the square wave signal at last, so as to get standard square wave signal. The actual application shows that the circuit has stable running with higher measuring precision.