To prepare a highly efficient electronic heat dissipation material, a porous composite material was prepared using soybean lecithin as a matrix and nanoalumina as a modifier via vacuum drying and biomimetic template casting. Simultaneously, an experimental system was constructed, including a heat source, temperature measurement, heat flux measurement, and environmental control modules (heat flux density 100-1000 W/cm2, sampling interval 0.001 second). A 3-D simulation model was established using ANSYS FLUENT (grid size 650000-780000, time step 1⋅10-4 second). Results show that the optimal parameters were a soybean lecithin-alumina ratio of 8:2 and a biomimetic pore size of 20 μm. The material achieved a thermal conductivity of 1.92 W/mK (8.7 times higher than that of pure soybean lecithin), which has a thermal conductivity of 0.22 W/m⁻K. The thermal response time was 0.11 seconds at a heat flux of 500 W/cm2 (a 42% reduction), and the steady-state thermal resistance was 0.18 Kcm2/W (meeting the requirements of electronic equipment). The simulated and experimental temperature-time curves were in good agreement, with a maximum error of 3.8% (≤5% tolerance). The relative error in the internal thermal resistance between 300 W/cm2 and 800 W/cm2 was ≤4.2%, validating the reliability of the model.