Mud refrigeration system is very important in the drilling process of gas hydrate sampling. This article describes the structure and working principle of the gas hydrate mud refrigeration system developed by Jilin University. The field application tests were made in Qiangtang basin, Muli basin and Mohe basin, the test results show that the application scope of this refrigeration system is wide with stable and reliable performance, and can be used in gas hydrate drilling in high altitude and high latitude permafrost regions and some other special areas.