The invention discloses a control circuit of a hot pressing welding machine. The control circuit comprises a signal display circuit, a button control circuit, a buzzer circuit, a PLC control circuit,a voltage regulation circuit and a driving circuit; the output end of the button control circuit is electrically connected with the input end of the PLC control circuit; the output end of the PLC control circuit is electrically connected with the input ends of the signal display circuit, the buzzer circuit and the voltage regulation circuit; and the output end of the voltage regulation circuit iselectrically connected with the input end of the driving circuit. The control circuit is higher in production efficiency and yield rate and lower in manufacturing cost.