Abstract: To deal with the increasingly severe thermal issues in integrated circuit, the flow and heat transfer characteristics of the fluid in the double-layer channel which have double-layer heat source were numerically simulated, and the results were compared to the single channel which has single heat source. Due to the interaction between the two channel layers, the heat source temperature of the upper channel and the thermal resistance of the lower channel were reduced by about 2℃ and 10%, respectively. The heat transfer performance was optimized by reducing convective thermal resistance. Micro-pin fin and fan-shaped reentrant cavities were arranged on the original rectangular channel structure. Results show that the heat source temperature of the lower channel is reduced about 11℃ by the new channel. The thermal resistance is reduced and the system performance is improved.