The invention discloses a safe positioning pin mounting device. The safe positioning pin mounting device is mainly composed of a fixed base, a positioning device and a pin punching device. The positioning device is mainly a fixed check block, the pin punching device is mainly a fixed box body, a seal space is arranged in the fixed box body, a control device is arranged at one end of the fixed boxbody, a protection device is arranged on the fixed box body, the center of a seal bottom plate is fixedly connected with an extrusion rod, and a top rod is arranged at the center of an airtight plate;when the device works, the device sleeves a positioning rod by virtue of positioning pin hole on two objects, unstability and dangerousness of manual holding are reduced, a rotating handle can control pin punching and recovery actions of the device, meanwhile, the seal cavity is inflated with a certain amount of air, when the pressure in the device reaches the critical point, a seal plate can bepushed upwards, the gas in the seal space can be discharged out of a connection hole, a middle through hole and a pressure reduction hole, and damage caused by too large pressure in the device is prevented.