Abstract: In order to solve the problem of heat dissipation for electronic devices with high heat flux, an optimal design of micro/mini-channel heat sink was presented by BOBYQA (bound optimization by quadratic approximation) algorithm combined with CFD software. The objective function was overall thermal resistance, and the constraint condition was pumping power consumption. The optimal results were calculated under unlimited and constrained height of heat sink. The results indicate that narrow and deep channel is more beneficial to heat transfer. Meanwhile, the optimal results under different pumping power were calculated, and the results indicate that the optimal thermal resistance decreases with increased pumping power. While, with continuously increased pumping power, the decrement decreases.