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 are added to the straight microchannel heat sink finite element model, which was constructed by using ANSYS finite element numerical simulation, and thermal-fluid coupling simulation analysis is carried out. Then, the impact of different flow channel numbers and different metal column structure arrangements as well as metal column diameters and lengths on the heat dissipation effect is studied. The simulation results show that the microchannel heat sink with 13 flow channels and a metal silver heat conduction column with a diameter of 0.25 mm and a length of 0.625 mm performs the best in heat dissipation performance. Compared with the straight microchannel structure before optimization, the heat dissipation effect is improved by 8.72%.