The invention provides a method for acquiring HRV based on a piezoelectric sensor. The method comprises the steps that non-contact signals are collected; BCG signals are separated; the BCG signals aresubjected to noise reduction treatment; HRV time domain parameters are calculated; HRV frequency domain parameters are parsed. According to the method, the problem is solved that existing wearable products need to be directly in contact with objects to be tested when collecting signals and limit motion of the objects to be tested so that inconvenience can be caused, a pressure sensor is used forcollecting the signals, whole physical characteristics of the BCG signals can be completed retained, and analysis based on the BCG signal cardiac cycle, the HRV and the like is more precisely supported. According to the method for acquiring HRV based on the piezoelectric sensor, HRV time domain parameters SDNN and PNN50 and HRV frequency domain parameters TP, HF, LF and LF/HF can be precisely acquired and are matched with various established healthy models, analysis of the individualized health trend, anti-pressure ability, fatigue index, sleeping ability and the like of testers is achieved, and then the heart health trend, anti-pressure ability, fatigue index and sleeping ability of the testers can be precisely judged.