The temperature of coal core directly affects the gas loss during coring. In order to reduce the error of gas loss prediction, the evolution law of coal core temperature field during coring is studied by method combining experiment and numerical simulation. The field coring temperature measurement tests with coring depth of 40 and 60 m were carried out. The 3 stage thermodynamic model of coring drill bit-coring tube-coal body was established and compared with the test, which verified that the thermodynamic model was reliable. A thermodynamic model of coring drill bit-coring tube-coal body-coal core in the process of coal seam coring was established, and the evolution law of coal core temperature in the process of coal seam coring with different coring depths was numerically analyzed. The results showed that the core tube generated heat by rubbing with the coal wall during the coal coring advancement stage. In the drilling stage, the drill bit generated heat by cutting the coal seam and rub with the coal wall. During the withdrawal stage, the coring tube and the gas in the hole conducted heat exchange and heat dissipation. The temperature of the monitoring point of the coring tube measured at different coring depths was consistent with the temperature change law of the simulation results, with an error of ±10%, which fully showed that the thermodynamic model of coring was feasible. During the coring simulation, heat was conducted from the drill bit to the inside and bottom of the coal core at the same time. While the temperature increased with time along the axial and radial directions, the peak temperature decreased with time due to heat exchange with the gas in the borehole. When coring coal seams with different depths, the final temperature of the coal core center increased exponentially with the depth.