To identify the shock generated sources of shear type explosive bolt, four kinds of explosive bolts with different states including preload, no preload, no piston shear and only propellant combustion, were designed. The decoupling of four kinds of shock sources including the collision of propellant combustion, piston shear weak surface, end of piston stroke and preload release, was realized. Their acceleration response at 15 cm from the shock source center on 60 cm×60 cm×1 cm equivalent aluminum plate were measured by using the piezoresistive accelerometer. On this account, the shock response spectrum of various source was calculated and compared with the overall shock response spectrum. Results show that the characteristics of different shock sources are different, the shock induced by propellant combustion is mainly caused by high frequency, while the shock caused by the collision of the piston shear weak surface and the end of piston stroke is concentrated in medium and low frequency. The preload release is major contributor to the overall shock response output, accouunting for approximately 57.51%, while the contributions of three shock sources of propellant combustion, piston shear and piston impact are equivalent.