<p>To today, molybdenum/silver (Mo/Ag) laminated metal matrix composites (LMMCs) have been employed as viable alternatives to traditional Ag interconnectors in space solar arrays, aimed at promoting the lifespan of low Earth orbit (LEO) spacecraft operated by the European Space Agency (ESA). The interface between Mo/Ag LMMCs and solar cells is achieved via PGRW. This study explores the PGRW mechanism using finite element simulations and experiments, focusing on three welding modes: constant voltage, current, and power. Orthogonal experimental designs guide the welding process, and the resulting joints undergo tensile testing for evaluation. Following that, the PGRW process was examined under the ideal circumstances of three input modes. A 2D axisymmetric model was created to replicate the phenomenon of PGRW. The thermal-electrical–mechanical coupled PLANE 223 element was implemented using the ANSYS software. The contact region and resistance have been verified. To solve the large thickness differences between the workpieces, the central region was depicted to investigate two widely varying dimensions together. The findings indicate that the maximum temperature reached during the welding procedure is below the melting point of the underlying material. Concurrently, the electric current can pass through the interface connecting Mo/Ag LMMCs and solar cells. The primary mechanism of connection in this PGRW process was determined to be interdiffusion and recrystallization induced by electrode pressure and resistance heat. The projected welding voltage and current exhibited a strong correlation with the empirical findings. It is implied that the strength of the connection will rise as the length of the joint is extended.</p>