Safety lock device for identifying child retention in vehicle and application method

The invention relates to a safety lock device for identifying retention of a child in a vehicle. The safety lock device comprises a safety seat arranged in the vehicle and a strap worn by the child. The strap comprises a front connecting block, a rear connecting block, a left shoulder strap, a right shoulder strap, a left waistband and a right waistband; one end of the left shoulder strap and oneend of the right shoulder strap are fixedly connected with the rear connecting block, and the other ends of the left and right shoulder straps are fixedly connected with the front connecting block; one end of each of the left waistband and the right waistband is fixedly connected with the rear connecting block, and the other end of each of the left waistband and the right waistband is provided with a buckle; a clamping groove, an electric lock, a first sensor, an alarm and a power supply are arranged on the front connecting block; a positioning groove is formed in the rear connecting block, two iron sheets and a touch