Embodiments of the invention disclose a power dispatching accident handling scheme preparing system and power dispatching accident handling scheme preparing method based on OMS. With the system and the method, maintenance plans can be scheduled in a rolling way, and a monthly plan advanced statistical analysis display function is achieved. The system comprises an information network module, a platform service module, a support module, a resource management module, an application service module, and a dispatching module. The information network module is used for storing grid information, grid management data, grid plan data, grid operation data and grid model data; the platform service module is used for getting a calculation result according to the grid management data, grid plan data, grid operation data and grid model data; the support module is used for providing an application interface and a service platform; the resource management module is used for controlling and analyzing virtual resources according to the calculation result and storing resource data; the application service module is used for getting an analysis result according to the resource data stored in the resource management module; and the dispatching module is used for dispatching power according to the grid information and the analysis result.