All systems of micro air vehicle with strict limitation of weight and size must accomplish the mission in the conditions of low noise, long-range flight, and fast response. The requirement for accuracy is pretty restricted. This study explores the combination fulfilling the requirement, and utilizes power supply and micro components of transmit system available in the market to carry out optimal combination. We planned to select battery, motor, propeller, transmitter, receiver, and electrical transmission to carry out optimal combination to be used as power supply system of UAV (unmanned aerial vehicle).