As the basis for the control of fuel injection and air-fuel ratio feedforward in the electronic control system, the in-cylinder intake air mass is essential for torque control and emission performance. To more simply and accurately estimate the in-cylinder air charge, a control-oriented model for the intake air is proposed in this paper, and based on the Simulink software, the intake model is further established. By introducing the GT-POWER simulations to assist the calibration, the calibration of heat transfer factor of the intake port, the key parameters of the in-cylinder trapped gas and the actual valve flow area is completed in the intake model. Finally, the calculation results of the intake model are compared with the simulation results and test results. The findings show that the calculation errors of the steady-state intake air mass are all within 5%, indicating that the proposed intake model provides a more feasible method for engine system control.