Tar-rich coal is a kind of coal resource with the properties of coal, oil and gas, mainly occurring in middle and low rank coal,with the characteristics of high tar yield. In situ pyrolysis of tar-tich coal is a technology that produces small molecule oil and gas by un⁃derground heating without mining, thereby achieving efficient and clean utilization of tar-tich coal resources. In order to clarify the influ⁃ence rule of multiple factors in the heat transfer process of in-situ pyrolysis of gas injection and explore the contradictory relationship re⁃stricting the heating rate in the heating process, a three-dimension model of coal seam, heating well and production well was constructedby using Fluent numerical simulation method. The influence of factors such as heating medium, fluid velocity, fluid temperature and frac⁃ture distribution on the overall temperature field distribution of coal seam was studied. The numerical simulation results show that there isno significant difference in the effect of different heating media on the temperature of coal seam. Compared with water vapor andnitrogen, carbon dioxide as the heating medium has a relatively better effect. The proportion of effective heating zone cannot be increasedto more than 25% with different flow rates under the heating condition of a single fracture, and the average temperature of coal seam is alsolower than 380 ℃ . The overall heating rate can be increased significantly by increasing the temperature of heating medium.When increas⁃ing the temperature of the heating medium by 50 ℃ , the effective heating area can be increased by 8% fractures, and the average temper⁃ature of the coal seam is increased by 29 ℃ . Under the heating conditions of three cracks, the heating rate is greatly improved comparedwith that of single well mode, and the temperature of the entire coal seam can be raised to 100% effective heating range within 2 years.The uneven fluid distribution in multiple transverse fractures can be improved by adding longitudinal fractures. The influences of differentfactors on heat conduction and utilization in the pyrolysis process of tar-tich coal are obtained, which is conducive to the enhancement ofheat transfer and the improvement of heat utilization efficiency in the heating process of tar-tich coal.