The utility model relates to an explosive synchronous switch, characterized in that a first nylon sleeve and a second nylon sleeve are mutually embedded to form a cylinder, the second nylon sleeve is provided with a groove structure, the first nylon sleeve is provided with a nylon side cover, the center of the nylon side cover is provided with a detonating cord connection hole, the center of the cylinder is provided with a main explosive, one end of the cylinder is connected with the detonating cord connection hole, the main explosive is arranged inside a copper pipe, a first switch electrode passes the first nylon sleeve and is connected with the copper pipe, a second switch electrode is annular and is arranged at the outer ring of the copper pipe, between the second switch electrode and the copper pipe 6 there is provided the insulating first nylon sleeve, and the lead wires of the two switch electrodes thread out of the first nylon sleeve. The explosive synchronous switch is suitable for an explosive detonation performance test under a pulse high voltage, and has the characteristics of being low in cost, simple in structure and adjustable in pulse width, etc.