The invention relates to the technical field of ship power systems, in particular to a radial grid structure and a control method of a pure battery-powered ship comprehensive power system. Its grid structure includes DC busbar, AC busbar, battery pack, DC / DC converter, DC / AC inverter, propulsion frequency converter / rectification and charging integrated device, DC / DC converter input terminal and battery pack There is an isolating switch connected between them, a first DC switch assembly is connected with the DC busbar, a second DC switch assembly is connected between the output end of the DC / DC converter and the DC busbar, and at least one section of the DC busbar passes through The sequentially connected fourth DC switch assembly, DC / AC inverter, and first AC circuit breaker are connected to the first AC busbar, and each section of DC busbar passes through the sequentially connected third DC switch assembly, propulsion frequency converter / rectifier The integrated charging device and the first AC contactor are connected to a section of the second AC busbar, and each section of the second AC busbar is connected to a propulsion motor through a second AC contactor.