To realize the continuous pumping source output of high-power semiconductor lasers, we design a stacked structure of multi-tube semiconductor lasers based on a microchannel heat sink packaging. Based on the simulation using finite element analysis software, this structure can expand the heat transfer channel of a single-tube semiconductor laser by assisting heat sink and cylindrical fins inside the microchannel. Additionally, the heat conduction effect is enhanced compared with the traditional groove microchannel. Furthermore, the oblique fin structure is optimized to control the water flow rate and promote the mixed flow effect, further improving the heat dissipation performance of the microchannel and power fitting on multiple single tubes under its packaging. The theoretical maximum output power can reach 128.75 W, which can realize the pumping of multi-tube semiconductor lasers in continuous working mode and meet their heat dissipation needs under the premise of low cooling power consumption required for microchannel heat sinking.