Abstract: In this paper, the energy monitoring system scheme for induction quenching machine based on PLC is proposed. The communication data format between the upper computer and the PLC are provided. The PLC related main program and interruption program are designed. Functions are fufilled, including the collection of DC voltage and current during induction heating, scale transformation, calculation of heating time and power, alarm setting, on/off control, etc. Through on-site running, the entire PLC control program can work well and get accurate result.