Abstract: Due to the material and assembling process characteristics, once the failure of the soft interconnects could induce total lost. This paper mainly focuses on the conversion of the coaxial-connector to microstrip, a new and reliable method was presented by the high-frequency simulation HFSS and investigated on the module samples, which can effectively prevent the problem of substrate fracture. The results show that the micro-resistance spot-brazing of gold microstrip-coaxial conversion was verified as the optimum design through introducing the Au-Sn solder welding process, which ensures the reliability of the microstrip-gold ribbon joint. The Au-Sn brazing filler shows a well-wettability microstructure, and the IMC compound with a double-layer structure and generated non crack at the interface of the welded joint. And the insertion loss of this brazing joint gold-coated strip was tested to be less than 0.2 dB in the bandwidth of DC~10 GHz. The spot-brazing transition was significantly extended the flexible interconnection methods to the aerospace product.