The invention provides a smart power grid business-oriented full-optical flexible-granularity switched network architecture and method. The method has a characteristic of having a large granularity range for business in a smart power grid, and independently divides network resources from two dimensions, i.e., the time domain and the frequency domain; in the time domain, rapid optical path switching is performed mainly through a whole network time synchronization technology-enabled high-speed optical switch, in the frequency domain, flexible frequency spectrum width selection is performed mainly through a variable-bandwidth optical transceiver, and resource division of the two dimensions is independent and is carried out under control of a network central control unit; resources of the time domain and the frequency domain form two-dimensional resource blocks in the network, and can be used for being matched with network business; and a time/frequency two-dimensional resource allocation method running in the controller can allocate appropriate network routes and link resources according to the requirements of intelligent power grid business, thereby ensuring effectiveness of resource allocation.