This paper focuses on the application of physical principles in the cooling and thermal management of electric vehicle electronic equipment, examining the thermal management problems caused by the increasing power density of electronic equipment. First, the heat generation mechanism of power electronic devices and battery systems is analyzed, and the application of heat conduction, convection, and radiation principles in cooling is explained. Innovatively construct a multi-physics field coupling algorithm and an artificial intelligence-based thermal management strategy optimization algorithm, and compare and analyze the temperature distribution and cooling system performance under different working conditions through the construction of an experimental platform and the establishment of a simulation model. The simulation results demonstrate that the proposed algorithm can accurately simulate the heating and heat dissipation processes, with a temperature prediction error controlled within 3%. Experimental verification shows that the multi-physics coupling algorithm achieves <3% error by dynamically coupling heat transfer, fluid-flow, and electrical fields, outperforming traditional methods (error >5%). The research provides theoretical and technical support for efficient thermal management of electric vehicle electronic equipment.