Improvement Form of Combination Grid Method

In solving special projection,combination grid method produces low precision numerical solution.This paper puts formard a new combination grid method which can improve computation form.This method has two sets of grids in the whole area,coarse grid,and fine grid.They are analyzed alone in the respective region,and do not affect each other.Numerical solution reaches its precision on coarse grid and its precision on fine grid.This method can improve numerical solution precision.