Two kinds of remote control methods, wired control system and wireless control system, are being currently applied in brushless DC motors, with the former one requiring additional signal lines and the latter one requiring remote interaction modules. In view of the above-mentioned disadvantages, a method has been proposed to realize the transmission of speed control signals in the form of controlled rectifier signal waves, thus achieving the remote speed control of Brushless DC motors. The system consists of rectifier control unit and speed control unit, with the former one sending controlled rectifier waves and the latter one receiving the signal waves and realizing the speed regulation. The research results show that this method can realize the remote control of brushless DC motor speeds and directions by using the power lines without additional control signal lines.