The invention relates to the field of detection of internal leakage of valves, and discloses a detection device for internal leakage of the valve. The detection device comprises a sound signal detection module used for detecting a sound signal on a pipeline provided with the valve (204), an adjusting piece used for adjusting the installation pressure of the sound signal detection module, a pressure detection module used for detecting an installation pressure signal of the sound signal detection module, an acquisition module used for acquiring the sound signal detected by the sound signal detection module and the installation pressure signal detected by the pressure detection module, and a signal sending module used for sending the sound signal and the installation pressure signal which areacquired by the acquisition module. According to the technical scheme provided by the invention, a problem of continuous online acquisition of internal leakage signals of the valve in the petrochemical field is solved, and the signal acquisition stability and effectiveness of the detection device for the internal leakage of the valve can be improved.