Abstract: With the development of science and technology,high power solid-state transmitter module is more and more used in satellite-borne products,but the satellite-borne solid-state high power technology is limited by the multipaction Phenomena in the vacuum.This paper analyze the position where the multipaction always happens in the solid-state planar circuit on the basis of mechanism of twice-electron-doubling-effect and electromagnetic field simulation,and a kind of specific PCB assembly structure is adopted to avoid the coming-up of the lacune,where the multipaction would produce,meanwhile on the surface of the PCB the film PARYLENE is vacuum-plated to reduce the multipaction threshold of micro-strip line.The high-power transmitter modules that adopt the technology mentioned above is working normally in the vacuum environment with the maximum peak power over 350W,no multipaction occurs.