In view of the electromagnetic interference existing in the well, it can greatly interfere with the voltage signal of the operational amplifier terminal collected by the dynamometer, and then affect the accuracy of the pressure value measured by the sensor. The design uses the domestic HC32L176 micro controller unit as the main control chip. Develop a dynamometer which uses the chip. Collect the voltage signal through the oscilloscope. Select the appropriate wavelet basis function, the number of decomposition layers, threshold rule and threshold function to decomposesignals containing noise. Filter out the high-frequency components of different layers,and then reconstruct the signal to obtain the denoising signal . Through Matlab simulation and practical test, the results show that the wavelet transform can achieve a good denoising of the collected voltage signal, and improve the reliability and stability of the bolt and cable dynamometer.