Abstract: In the context of phased array antennas developing towards integration and miniaturization, engineering practices widely adopt SMP (SubMiniaturePush-on) connectors arranged in an array format for design purposes. However, during actual production, as product integration increases, the number of connections to be welded significantly rises, leading to welding quality issues such as connector tail protrusion, misalignment, and insufficient solder fill in the welds. In response to these challenges, this study proposes a specialized fixture designed specifically for SMP connector welding. By optimizing fixture spring wire diameter, dimensional parameters, and implementing modularized expandable designs, we have addressed the issue of low welding quality pass rates for multiple SMP connectors. The solution achieves high-precision and highly reliable assembly welding of SMP connectors, with solder fill in all welds reaching over 95%. This research provides an effective technical means to solve precise welding problems for high-density RF connectors, satisfying the needs of various engineering applications across different types.