The invention discloses a disengaging method of architrave and mischzinn of a circuit board element and a device thereof. A metallic mesh-shaped conveyor belt is mounted on the frame; a heating device is installed below the conveyor belt; a circuit board is fed in from the front end of the conveyor belt and is transferred by the conveyor belt to the position above the heating device for continuous heating, and during the process, some of the architrave and the circuit board are disengaged automatically and fall into a receiving basin below the conveyor belt; at the same time, harmful gases produced in the heating process are exhausted by an exhaust pipe and are discharged into the air after the deodorization treatment; a vibration device and a recovery device are installed and connected to the position below a rear roller of the conveyor belt; a vibrating grid vibrates at high frequency, and the molten mischzinn and the architrave on the circuit board fall off with the function of the vibration and fall into a recovery container. The heating method of the invention is capable of completely removing and recovering the tin and the mischzinn, the method is simple, practical and efficient, and effectively protects the air from contamination, thereby the method is environment friendly.