The invention discloses a measurement device for an underwater needle plate electrode discharge shock wave. The device comprises a high-voltage impulse power supply system, a photoelectric combined diagnosis system, a schlieren diagnosis system and a pressure wave measurement system, wherein the photoelectric combined diagnosis system is used for obtaining voltage, current, light intensity and spectral signals in a discharge development process as well as the time domain image of a discharge channel; the schlieren diagnosis system is used for measuring the propagation characteristics of the underwater shock wave; and the pressure wave measurement system is used for researching an impact wave amplitude value and a development process. In addition, the invention also provides a correspondingmeasurement method. In the measurement device and method for the underwater needle plate electrode discharge shock wave, measured signals comprise time domain signals, including a photoelectric signal (voltage, current and luminescence), a schlieren pattern, a pressure wave and the like, and the device and the method can be used for researching the complete period physical process of the plasma and impact wave development of the underwater needle plate electrode under impulse voltage excitation.