A closed-loop heat equalization system includes a heat gaining device installed within a natural thermal energy storage body, and a heat releasing device having multiple flowpaths, the heat gaining and releasing devices being connected by pipeline structures to form a closed-loop flowpath for a heat exchange fluid. An outwardly expanded arc-shaped structure may be included at one or more turning locations in the pipeline structures. The pipeline structures may include an operation port and sealing plug at a top corner of the closed-loop flowpath, and an auxiliary heating/cooling device or fluid pump controlled by a sensing device and an electric energy control unit.