To achieve precise modeling of turboprop engines in flight simulation, this study provides an in-depth analysis of the component operating characteristics of the turboprop engine under the constant speed control law. Based on these characteristics, we integrated the core engine using a simplified component model. A 95.5% match for the acceleration process is obtained by approximating the model's dynamic processes using second-order transfer functions, which are introduced as a means of improving the accuracy of dynamic modeling. In addition, to enhance model generality, normalization processing is conducted based on similarity theory principles, enabling extrapolation within the flight envelope. In the validation phase, we carried out a simulation and comparative validation of the model using publicly available data on the amount of overall performance of the AH-20M turboprop engine, as well as some experimental and simulation data. The results showed that only a limited overall performance parameter data was needed to quickly build an engine model with certain steady-state accuracy and reasonable dynamic changes. The model is an effective and precise way to model turboprop engines in flight simulation, and it satisfies the performance and functionality criteria of flight simulation.