A distributed power supply system includes a plurality of energy modules, a plurality of power conversion modules, and a bus voltage controller. The energy modules are electrically connected to a DC bus via corresponding power conversion modules, and the bus voltage controller is connected to the power conversion modules. An energy regulation method includes: acquiring at least one energy state parameter of the corresponding energy module and computing a base value of the respective power conversion module; generating a normalized control signal based on a bus voltage of the DC bus and transmitting the control signal to the power conversion modules by the bus voltage controller; and obtaining a specified control reference value of the power conversion module depending on the control signal and the base value and regulating the corresponding energy module depending on the specified control reference value by the power conversion module.