As is well known, thermal effect is a major bottleneck limiting the development of high-power and high-energy lasers. During the process of producing high-energy lasers, a large amount of waste heat is generated, which affects the beam quality of high-energy lasers and even their normal operation. In order to ensure the stable operation of the high-energy laser and study the heat distribution state of its working material in the process of heat dissipation, this paper establishes a dual end water entry microchannel heat dissipation model for high-energy Zig-Zag Flat noodles laser amplifier. The heat dissipation of microchannel and cavity heat sink is compared under rated conditions using CFD simulation software. The variable parameters of the model are also studied: channel height, fin thickness, And the impact of water flow rate on heat dissipation performance. Simulation studies have found that the cooling effect of the microchannel heat sink proposed in this article is better than that of full cavity water cooling. The microchannel heat sink controls the maximum temperature difference on the crystal surface within 4 ℃, and the surface temperature is also reduced by 32%; Optimizing channel parameters within the allowable range of pressure drop can further improve the cooling effect by 10%, achieving distributed and efficient heat dissipation of gain media.