Abstract: To solve the problem of the vibration response overrun of a space vehicle's instrument installation board excited by the acoustic load, a vibration suppression method of adding a constrained damping layer is put forward. First, the application and the principle of the vibration reduction of the constrained damping layer are discussed. Then with the typical instrument installation board of the vehicle as the research object, the vibration reduction is analyzed by comparing the vibration response before and after adding the constrained damping layer with the same acoustic excitation. The results show that reduction of the RMS acceleration response in the place of the instrument installation is nearly 1.56dB(16.4%) after the constrained damping layer is added to the instrument installation board.