Abstract: Focusing on the issue of relatively low heat dissipation efficiency of complex structures in straight microchannels on LTCC substrates, a metal silver heat conduction column structure is set on the microchannel packaging layer to enhance the heat dissipation effect of straight microchannel heat sinks. Firstly, three different numbers of flow channels and ten metal column structures were added to the straight microchannel heat sink finite element model, which was constructed using ANSYS finite element numerical simulation, and thermal-fluid coupling simulation analysis was carried out. Then, the impact of different flow channel numbers, different metal column structures, and metal column diameters and lengths on the heat dissipation effect was studied. The simulation results show that the microchannel heat sink with 13 channels and 0.25 mm diameter, 0.625 mm length silver heat conduction columns performs the best in heat dissipation performance. Compared with the straight microchannel structure before optimization, the heat dissipation effect is improved by 8.72%.