Abstract: MEMS pressure sensors are widely used in aerospace and other industrial fields. With advancing science and technology, higher requirements have been placed on their pressure-bearing capacity and structural strength. The structural design of high-range MEMS pressure sensors is a core crucial part of sensor development, and reasonable structural design with matched metal base materials can effectively improve sensor pressure resistance and operational reliability. This paper adopts thermal conduction and mechanical principles to simulate and calculate reasonable welding penetration of high-range MEMS pressure sensors, optimizing applicable welding processes and parameters. Meanwhile, structural optimization of the MEMS pressure sensor is conducted via multi-physics coupling modeling; the optimal structural scheme is obtained through simulation analysis and verified by engineering demonstration. This research improves the structural performance, stability and reliability of MEMS pressure sensors under harsh high-pressure, high-overload and high-temperature conditions, providing theoretical basis and data support for engineering applications of high-range MEMS pressure sensors in extreme environments.