The embodiment of the invention discloses a signal gain control method and device, and the method comprises the steps: carrying out the analog-digital conversion and digital signal processing of an obtained first signal, and obtaining a second signal; carrying out the interleaved amplitude statistics of the second signal, and determining the interleaved statistical mean value; determining a gain control code according to the interleaved statistical mean value and a preset threshold value, and carrying out the gain control of the signal according to the gain control code. According to the embodiment of the invention, the method and device can automatically adjust the gain of the signal received by a system receiving link, and improve the remote sensitivity.