AC motor rotor end ring and conducting bar welding,the whole induction heating by induction heater on the end ring bar,realize induction brazing,therefore,to realize the welding of rotor end ring copper bar,the induction heater is a key link of development. This article through several aspects of rotor end ring bar welding induction heater design principle,induction heater composition,induction heater and end ring assembly form,application of induction heater evaluation to develop a reliable induction heater,to solve the problem of AC motor rotor copper end ring and guide bar welding integral induction heating,guarantee the motor rotor end ring bar welding quality.