Abstract: In view of the fact that the data processing of Hotline Method can only get the thermal conductivity and can not master the distribution of the temperature field of loose coal, based on the experiment, the Fluent numerical simulation method is used to analyze the temperature distribution of two kinds of different particle siz e coal samples. The results show that the temperature distribution can be used to determine the stage of heat transfer between hot wire and loose coal, and the thermal conductivity can be obtained more accurately by the experimental data. The thermal conductivity of loose coal is smaller and the temperature transmission range is sma ller, which is suitable for small size of the experimental device for testing. The numerical simulation combined with Hotline Method can get the thermal conductivity at th e same time to understand the distribution of temperature, which has a big significance on the test data fiting accuracy and test device design.