The invention discloses a local grid increment dynamic partitioning method applied to a fixed value checking system. The automatic partitioning of an incremental part of a power grid model applied tothe fixed value checking system can be achieved, with a grid basic model as an initial calculation model, the automatic partitional of a newly added power grid is carried out with a plat station as aunit, and a dynamic partitioning algorithm is combined to ensure the efficiency and correctness of whole grid tuning parameters namely a current maximum value and a branching coefficient.