The heat dissipation effect of the interleaved micropinfin heat sink was studied by numerical simulation, and the influence of the array spacing and height of the pin fins on the wall temperature and pressure drop of the heat sink was studied. Experimental results indicate that the press drop increases nonlinearly with the decreasing array spacing and height of the pin fins, while the wall temperature increases with the increase of the pin fin spacing, but it shows a fluctuation trend with the increase of the pin fin height. Based on the above research, it further optimizes the lateral spacing, longitudinal spacing and height of the microneedle fins with the method of response surface approximation. The pressure drop can be reduced by a maximum of 61.11% after optimization.