With the extensive application of GNSS (Global Navigation Satellite System) around the world, the technology of global navigation and orientation technology has run to a brand-new stage. With the development and improvement of China's Beidou and Russia's GLONASS system, and the application of the multi-band and multi-mode navigation satellite receiver will be the hotpot of the research and application about satellite navigation system in the future. On the basis of analyzing the each characteristics and further developments of the GPS, Beidou “Double Star” and GLONASS system, we studied the multi-mode receiver fusion technology of the satellite navigation system through the layers of the hardware circuits which base on FPGA/DSP and data fusion etc.