Heat transfer model of buried pipe heat exchanger is established first, and solved by the ANSYS finite element simulation software. Model is verified by experiment, average error is 6.4%. On the above basis, return water temperature of buried pipe and soil temperature are analyzed during whole operation. Through whole cooling season, outlet water temperature of buried pipe increased by 6.7°C, up to 21.2°C. After 45 days on transition season, temperature reduced 3.2°C, up to 18°C. Within one year, temperature difference is above 1.1°C before-and-after heating and cooling operation. It reveals that soil temperature cannot fully recover only by natural heat conduction and soil heat storage appears, which should be paid more attention in the project.