Abstract: A simplified gas flow domain model was applied to modeling and simulation of a bypass dual-spool mix flow turbofan engine,and the detailed calculation process and all formulas were presented.According to the engineering experience,a small-scale local iteration was introduced to reduce the time step of calculating the parameters in turbine components and significantly improve the solution.On a comparative basis,this method avoids large-scale iteration for solving non-linear equations,thus ensuring faster calculation of the full range aero-engine simulation program.This method is proved to provide enough calculation accuracy when the simulation results are compared with the test run data of engine.