The method is applied to a terminal device, the terminal device stores training sample data, and the training sample data includes a correlation spectrum characteristic vector of a reflected signal of a sounding reference signal (SRS) and a corresponding user gesture identifier. The method includes: transmitting, by the terminal device, a first sounding reference signal (SRS); receiving, by the terminal device, a multipath reflected signal that is of the first sounding reference signal (SRS) and that is reflected from a gesture-making object, and performing a related operation on the reflected signal and a signal template corresponding to the first sounding reference signal (SRS), to obtain a correlation spectrum characteristic vector of the reflected signal; and matching, by the terminal device, the correlation spectrum characteristic vector of the reflected signal against the training sample data, to recognize an input gesture.