Tar-rich coal, as a recognized distinctive type of coal resource, is a crucial strategic energy in China with enormous reserves. In-situ pyrolysis of tar-rich coal is a new technology that abandons traditional coal mining and directly extracts oil from underground pyrolysis.Previous studies on in-situ gas injection heating mainly focused on the exploitation and utilization of oil shale. Although the residual heat from block pyrolysis has significant economic benefits, the process of utilizing waste heat has received little attention.A two-dimensional large-scale model of the semi-coking area cooling of tar-rich coal was built in order to analyze the influence rules of cooling medium type, inlet velocity and temperature of cooling medium, initial temperature of semi-coke area, well layout, number of horizontal cracks, heating duration and inlet velocity of heating medium on the waste heat utilization process. The results demonstrate that the flow velocity of the cooling medium has a limited effect on the cooling effect of the semi-coking area. The contribution of the heating medium velocity to the average temperature rise is limited.CO2 as the cooling medium is favorable for the cooling of semi-coking area when compared to N2 and water vapor. The temperature uniformity of the semi-coke layer and the cooling efficiency can be improved by increasing the number of gas injection wells, but the location of gas injection wells has essentially little impact on semi-coking area cooling.The double horizontal fracture arrangement is sufficient to meet the requirements of effective cooling. By optimizing the parameters of the initial state of semi-coking area cooling, it is helpful to understand the temperature variation law of the cooling process, improve the utilization efficiency of waste heat, and provide a theoretical foundation for the entire process of in-situ thermal injection mining of tar-rich coal.