Application of soft bag leak detection machine in the composite film soft bag large transfusion seal check, without the need to change the mold can check the 3000ml, 1000ml, 500ml, 250ml, 100ml and various specifications of the soft bag products. Testing site for upper part of the bag body cover weld inspection, boat shaped interface and film welding on-demand can check once a. Equipment for automatic operation, equipped with automatic bag supplying device driven by a servo motor, a sensor, a bag is synchronous rotation is stopped without bag.