Using ANSYS software, the heat transfer process of hot water storage tank in spherical, cylindrical and square shapes was numerically simulated, and the distribution of the external wind velocity field and the temperature field under the same working conditions was studied. According to the change of average hot water temperature with time, it is concluded that spherical hot water storage tank can help reduce heat loss. Based on velocity field and temperature field distribution, it is found that the heat loss of the spherical hot water storage tank mainly occurs on the annular surface perpendicular to the windward side. By thickening the thermal insulation layer, it is possible to reduce the heat loss on the surface of the spherical water storage tank and improve the thermal insulation effect.