Abstract: The heat conduction process of energy pile in soil was simplified to a finite-length heat source model, and the three-dimensional heat conduction finite layer equation of soil with constant temperature and adiabatic boundary conditions was derived based on the differential equation of heat conduction and Galerkin method. By using the difference method to discretize the time term, the difference solution format of the finite layer equation of three-dimensional unsteady heat conduction in soil under the condition of finite long line heat source is given, and the finite layer analysis method of heat conduction in layered non-homogeneous anisotropic soil around the energy pile is established. The three-dimensional unsteady heat conduction problem is transformed into a two-dimensional expression within a number of layers, which simplifies the solution process of energy pile-soil temperature field distribution. The correctness of the finite-layer method of heat conduction for calculating the temperature field distribution is verified by comparing with the analytical solution, test results and finite element results, and the effects of the operation duration, the thermal conductivity of the rock and soil body around the pile and the site boundary conditions on the soil temperature field distribution are investigated separately by using this method.