Abstract: For the sampled electrocardiogram（ECG） signal，the varied noises often overlay the all frequency field of ECG.It is difficult to use the normal method to de-noising.In this article a non-line threshold filtering function h is introduced.The parameters of the h function in different wavelet scales is determined based on training signals，and then using the adaptive threshold filtering wavelet method to de-noising the ECG signal.Compared with the wavelet threshold de-noising algorithm，this method is validity in ECD de-nosing，and it has more advantages in keeping the ECG shape after de-noising.