A novel scheme of low power communication power supply with high power factor and soft-switching is presented, a power factor corrector and dc/dc converter of passive lossless soft-switching is based on a ML4803 IC control. DC/DC converter introduces a novel two-transistor forward soft-switching technique, which realizes zero-voltage turn-on and turn-off, with no additional switches. a communication power supply module is developed in this paper. It has the characteristics of rapid dynamic response, high power factor, high efficiency and small bulk ect.