Abstract: Thermal relays serve as critical overload protection devices in low-voltage electrical control systems; their temperature rise characteristics and the deformation behavior of their bimetallic strips directly determine the operational safety and stability of electrical equipment. Focusing on a specific model of low-voltage thermal relay, this study establishes a comprehensive simulation model integrating thermoelectric coupling and structural mechanics, based on the principles of heat transfer, mechanics of materials, and current conduction theory. Utilizing a simulation platform, the study conducts a step-by-step analysis of the relay"s temperature rise characteristics, as well as the thermal displacement and thermal thrust of the bimetallic strip. It identifies the temperature distribution patterns across key components and analyzes the deformation and mechanical behavior of the bimetallic strip under varying operating currents.