The invention discloses a line predicting and reforming system based on a power grid dispatching anti-error system and a working method of the line predicting and reforming system and relates to a system for predicating and changing line conditions at the intermediate and later stages of line reforming and a working method of the system. The line predicting and reforming system and the working method thereof can be used for realizing predication by misoperation-preventive locking and operating recommendation of whole-network equipment as well as reforming renewal. The line predicting and reforming system comprises a graphical interface module, a model data processing module, a layer mapping module and a misoperation-preventive locking control and operation recommendation module. The working method comprises the following step of (1) initializing; (2) analyzing; (3) establishing and mapping layers; (4) carrying out recommendation judgment; (5) giving an operation recommendation; (6) carrying out renewal judgment of drawings; (7) substituting an actual area chart; and (8) finishing predicting and reforming. The system disclosed by the invention can be used for furthest eradicating sequence error in power-on/power-off coordinated operation and has important significance on guarantee of safety production of power grid reforming. The power grid predicting anti-error system automatically adapts to topological structure change, and drawings for network reforming are maintained in advance, so that the use workload is greatly reduced.