The invention discloses a semi-automatic window breaking system. The semi-automatic window breaking system comprises a bottom box and a cover box hinged to the bottom box. A hammerhead, a compression spring, a draw cord, a sliding sleeve and a driving lever are installed in the cover box. The tip end of the bottom of the hammerhead stretches out of the bottom of the cover box, the top end of the hammerhead is connected with the bottom end of the compression spring, the top end of the compression spring is connected into the cover box in an abutting mode, the sliding sleeve is fixed to the hammerhead through a buckling block, one end of the draw cord is connected with the sliding sleeve, and the other end of the draw cord is connected to the bottom box. When the cover box swings outwards, the draw cord pulls the sliding sleeve and the hammerhead to compress the compression spring, when the sliding sleeve moves to the position of the driving lever, the driving lever is connected with a movable buckling block and drives the movable buckling block to be separated from a clamping groove, the hammerhead is separated from the sliding sleeve, and the hammerhead is made to rapidly stretch out of the bottom of the cover box under the effect of the compression spring, so that tempered glass of a car window is broken. The system is simple in device structure, convenient and reliable to use, high in distinguishing degree in an emergency and widely suitable for people, processing parts are relatively simple, assembly is simple and understandable, and the system is suitable for volume production, application and popularization.