The invention provides an embedded energy storage type multi-module series-connected photovoltaic DC (direct current) boost converter and an application method. The embedded energy storage type multi-module series-connected photovoltaic DC boost converter comprises multiple photovoltaic DC boost converter submodules which are connected in series sequentially, wherein each photovoltaic DC boost converter submodule comprises a hybrid energy storage module, an isolated type full-bridge DC-DC circuit, a two-way boost/buck converter and a photovoltaic array, the hybrid energy storage module is used for balancing power output by the photovoltaic DC boost converter submodule, the isolated type full-bridge DC-DC circuit is used for realizing voltage boosting and maximum power point tracking, and the two-way boost/buck converter is used for controlling output power of the hybrid energy storage module. The system can eliminate influence of input power mismatch on normal operation of the photovoltaic DC boost converter fundamentally, a low-voltage DC bus is not needed, meanwhile, reliability of the system is enhanced, and internal fault isolation is convenient; a header box is not required to be arranged, the system is convenient to maintain, and overall control response speed under the special condition of a power station is increased.