This chapter proposes a multi-dimensional turbofan engine overall performance calculation method that is coupled with a 0D/3D simulation model, which considers the effect of component geometry on aerodynamic performance to improve the accuracy of overall engine performance prediction. Using a mixed exhaust turbofan engine as the application object, on the basis of a zero-dimensional overall performance simulation program framework, the fan component and nozzle component in the overall simulation program are replaced by a tightly coupled method to obtain the 0D/3D multi-dimensional overall engine performance simulation results. The physical mechanism of the effect of the three-dimensional model on the overall performance is analyzed. The performance simulation accuracy under different-dimensional model mixing situations is compared with the experimental test data. Compared with the zero-dimensional model, 0D/3D coupling significantly improves the calculation accuracy for physical quantities at key locations, such as the turbine inlet temperature, and the simulation accuracy for performance parameters such as the overall engine thrust and fuel consumption rate can be improved by 2%. The use of component performance models of different dimensions for multi-dimensional simulation can effectively improve the overall aerodynamic performance simulation results for the whole engine, and the balance between calculation efficiency and simulation accuracy can be flexibly adjusted according to needs.