Method and device for detecting motion signal

The invention provides a method and a device for detecting a motion signal. The method for detecting the motion signal comprises the steps: an original echo matrix corresponding to a received echo signal is obtained; out-of-band noise abatement is conducted on the original echo matrix so that an out-of-band noise abatement output matrix is obtained; out-of-band interference and noise of the motion signal of the out-of-band noise abatement output matrix are filtered, the motion signal is reserved, and a noise abatement output matrix is obtained; the motion signal of the out-of-band noise abatement output matrix is filtered and the out-of-band interference and the noise of the motion signal are reserved so that a noise estimating output matrix is obtained; the noise abatement output matrix and the noise estimating output matrix are calculated so that a test statistic is obtained; and the motion signal in the echo signal is identified according to the test statistic and a judgment threshold corresponding to a set false alarm rate. According to the method, the false alarm rate can be reduced and effectively controlled.