Taking the first field of the right section at the left column of electrostatic precipitator (ESP) in a 440 t/h circulating fluidized bed (CFB) boiler as a research object, contrast tests of ESP performance were performed between high frequency power and fundamental frequency power. The results show that the dedusting quantity by using high frequency power has been improved 4.25% than that by using fundamental frequency power, in which the dedusting efficiency of the first field has been improved 4.54%. From the points of effective power's conversion efficiency and active power input, it is proved that high frequency power has obvious energy saving effect, and the payback period of power plant is 3.77 years. The selection method of high frequency power is suggested according to the value of apparent migration velocity of particle (ωk).