Abstract: Microwave wireless power transmission (MWPT) is one of the important new styles of power transmission in the future. It has wide application in military and civil field, such as, space solar power station (SSPS), power transmission for islet, recharging for UAV and energy satellite. According to the application requirement of energy satellite, based on high efficiency vacuum power devices, this paper extends the carrier frequency to Ku-band. In the paper, High Voltage Electronic Power Conditioner(HV-EPC)adopts single-stage resonant change technology which significantly reduces the switching loss of converter; Microwave source uses high efficiency traveling wave tube adopting pitch dynamic velocity gradient resynchronization technology and multi-stage depressed collector technology, which greatly improves the interaction and collecting efficiency. Schottky diode is used for microwave rectification applying multiplex synthesis technology reducing the insertion loss and adjusting the rectification efficiency. Based on the above technology, a Ku-band high-efficiency long-distance microwave wireless energy transmission system is built. The test results show that for 12. 5 GHz carrier frequency and 25 m transmission distance, the microwave transmitting power is 150W, and the total conversion efficiency of AC-to-DC is 5. 6%.