Abstract: The effects of temperature distribution on welding quality in high-frequency induction heating (HFIH) were investigated in order to improve the weld quality in HFW (high-frequency weld) pipe.According to the characteristics of induction heating,the secondary development on the ANSYS finite element software was carried out.Based on physics environment method and APDL language,the program of coupling of electromagnetic and thermal fields for process of high-frequency induction heating of HFW pipe and a 3-D FEM model were built up,and the temperature distribution rule of the coupling of electromagnetic and temperature fields was given.The simulation results for the production of steel pipe φ 219 mm show that the distribution of the array of small core is better,which meet the production well.