Electrocardiogram (ECG) detection in patients with heart health is an important technical means. Because the load of heart is added in motion, heart diseases are likely to be induced by signal. The detection of ECG in the moving state is more necessary. But the ECG signal, a weak bioelectrical signal, is susceptible to environmental interference. Especially in the state of motion, the ECG includes the main interference signals: motion jitter interference, frequency interference, baseline drift and capacitively coupled noise between the electrode line interference. This paper studies the noise signals. 50Hz band-stop filter, the right leg driven circuit and 0.1-150Hz band pass filter are used in the analog signal processing, and the wavelet transform algorithm is used in digital signal processing. ECG can be detected in a strong movement noise background. The results show that the sensor has the advantages of anti-interference, high fidelity, fast response speed and good stability.