A signal processing method provided in this application is applied to a terminal device, and the signal processing method includes: after an indication signal sent by a laser receiving sensor is received, processing the indication signal to obtain a target signal, where delay of the target signal relative to the indication signal is preset duration, a pulse width of the target signal is a target width, and the target signal is configured to trigger laser emission; and determining a start moment of laser emission based on the target signal and the indication signal.