The invention provides a metal structural part and coaxial cable non-contact heating tin brazing method. The method comprises the following steps: a workpiece is prepositioned on a transmission system, and is transmitted to a heating system; the workpiece includes a metal structural part and coaxial cable preassembly structure, a flux prepositioned in a welding point between a metal structural part and a coaxial cable, and a transfer fixture for positioning the preassembly structure; the non-contact thermal radiation heating is performed for the workpiece, so that the flux in the welding point is fully fused; and the heated and welded workpiece is cooled, so that the welding point is quickly solidified. Through fine labor division of welding device fixation, flux adding, heating and welding, the automation of all procedures is realized, the welding efficiency is improved, and the welding quality is guaranteed.