Initially we applied the same data structure to grid generation, with further research, we found that the overall calculation efficiency of such a design is not high, and it is difficult to maintain. Finally, we designed different data structures based on the different characteristics of the two parts, in the grid generation, more consideration is given to flexibility and maintainability, a method to determine the flux function through the boundary of a triangular mesh is given. This method first obtains the two-dimensional Euler equations in the normal direction of the boundary of the control volume element, in the system of projection equations, the flux along the tangent to the boundary can be regarded as passive convection, therefore, the one-dimensional Riemann problem solver can be directly used to calculate the flux function passing through the boundary of the triangular control unit. This method under various flow conditions, including supersonic pipe flow and subsonic isentropic flow with strong shock waves, all have high precision and good stability.