The invention discloses an intelligent hierarchical extension modular energy control system. The system comprises a main control device and a sub-control device. The sub-control device comprises a data acquisition module, a data communication module, a decoding execution module and a sub-controller implanted with an optimization algorithm; the sub-controllers communicate with a main controller ofthe main control device through an optical fiber channel; the main controller and the sub-controller adopt a bidirectional transmission mechanism; and a control strategy and a control algorithm are set in the main controller and are responsible for optimal operation and scheduling of the overall system. The control system adopts a cascade control structure of hierarchical regulation and control, can improve the control quality of main parameters by setting auxiliary parameters, and can realize effective data sharing, platform interaction and unified management, so that the energy management and scheduling level is greatly improved; and the system has good stability and expansibility, the actual working condition can be effectively controlled, and the working efficiency is improved.