The invention relates to an energy internet system based on series-parallel hybrid energy storage and a control method, and belongs to the technical fields of energy internet and energy storage. According to the energy internet system of the invention, the grid-connected operation and the island operation of the energy internet system are realized, the large-capacity series connection of energy storage batteries on the DC side and the investment in high power DC/DC converters are avoided, and the cost of the energy internet is reduced effectively by utilizing series-parallel energy storage units and energy storage group strings. According to the control method of the invention, each energy storage group string in the energy internet corresponds to a central controller, and the power distribution between the parallel energy storage group strings is realized by adjusting the output power and voltage of the energy storage group strings. Meantime, each energy storage unit corresponds to alocal controller, and the power distribution between the series energy storage units is realized by adjusting the output voltage of the energy storage units. Through the control strategy, each energystorage unit can participate in the power control of the energy internet flexibly, and the flexibility, reliability and economy of energy internet operation are improved.