Abstract: Appropriate frequency of high frequency power source shoulded be selected to obtain perfect soldered joint during high frequency induction brazing according to the physical performance of joint materials. Numerical selection model for the frequency and its arrange of high frequency induction heating power source was set up by means of numerical analysis. It showed that numerical analysis can be used as an important artifice for design of high frequency power equipment. Compared the analytical results from the numerical model with that of the traditional formula, it showed that the former is more accurate. Because the latter was derived from the plane electromagnetic wave spreading characteristic in electro-conductive inter-media, it was more suitable for the frequency selection of board structure high frequency induction heating. But for frequency selection of pipe-structure or more complex structure high frequency induction heating, the numerical analytical method will be better.