Grid geometry induced error reduction method for high-order finite difference flux solution

The embodiment of the invention provides a grid geometry induced error reduction method for high-order finite difference flux solution, and belongs to the technical field of calculation, and the method specifically comprises the steps: 1, generating a non-uniform and non-orthogonal body-fitted grid for a complex shape, and mapping a fluid control equation to a curve coordinate system through coordinate transformation, the complex shape comprises a machine body shape corresponding to an airplane, a train or a steamship; step 2, performing itemized decomposition on the convection flux corresponding to the complex grid under the curve coordinate system to obtain a first item of the convection flux and a second item of the convection flux; 3, performing flux splitting treatment on the first convection flux item and the second convection flux item by adopting a vector flux splitting format to obtain node positive/negative flux corresponding to the first convection flux item and the second convection flux item; and