In order to solve the problem of the thermal effect of the laser gain media, a configuration named “immersed thin-disk oscillator”solid laser cooled directly with flow was proposed. Under the repeated pumping frequency of 10Hz，a maximum output energy of 615mJ was realized. The optical-optical efficiency and the slope efficiency is 23% and 21% respectively. Based on the principle of fluid mechanics and thermodynamics，the thermal-flow-solid coupling model of lasing region was established. By using the software and the method of finite element analysis, the distribution characteristics of temperature field and velocity field were studied under the conditions of different flow rate and pump power. The wavefront aberration of the laser passing the gain region was simulated under the condition of liquid-cooled. The maximum optical path difference of the gain medium and coolant liquid are 0.7666λ and －4.7331λ respectively. The results show that the laser has a good thermal management performance.