This paper designs a portable ECG monitoring device, which has the advantages of low power consumption and wide application scenarios, and can monitor the human body electrocardiogram (ECG) in real time during exercise. In order to eliminate the noise interference in the ECG signal, especially the motion artifact (MA) interference, the optimization step factor is improved based on the traditional LMS algorithm, and the convergence speed of the adaptive process is accelerated, thus ensuring optimization. weight. The amount of misalignment near the coefficient is the smallest, and the amount of calculation of the weight coefficient update is reduced. The experimental results show that the algorithm can obtain clear and undistorted original ECG signals in the real-time processing of signals, which has the advantages of small calculation and good filtering effect.