Surface electromyography is the bioelectricity generated by the contraction of human surface muscles,whichcan reflect the activity of human muscles,It has important research value in the medical field.Because the surface EMG signal is a weak signal, the smaller noise can produce larger interference. Aiming at this weakness,In this paper, a surface EMG signal acquisition system with small volume, low power consumption and strong anti-interference ability is designed.AD8232 is designed as the acquisition chip, combined with amplification, filtering and analog-to-digital conversion circuits,and STM32 is used for data processing.Finally, the data is sent to the host computer through low-power Bluetooth.The test results show that the energy of surface EMG signal is mainly concentrated in 50~150 Hz,Above 300Hz, it obviously attenuates,and is greatly disturbed by low-frequency signals.After hardware filtering and wavelet denoising algorithm,Interference is well inhibit,Especially for low frequency interference.The system has strong anti-interference ability and reliability, and has a good market prospect.