Abstract: To provide energy loss loading conditions for the thermal analysis of Hall thruster, a thermal model of Hall thruster is developed. Based on the plasma theory, the mechanism of various energy losses in discharge chamber is analyzed, and related functions are established between these energy losses and operation, performance parameters and structural parameters. At last the complete thermal model of Hall thruster is obtained. The thermal model for LHT100 thruster is calculated. The following results under the steady operation are obtained: the beam energy loss is about 889 W, the energy loss at wall is about 300 W, the anode energy loss is about 44 W, the ionization energy loss is 43 W, and the radiation energy loss is 34 W, respectively. Taking these energy losses as loading conditions to perform finite element thermal analysis and using thermal balance to validate experimentally, the results indicate that the calculated values agree well with the experimental ones, the maximum error is no more than 5%.