During the qualification of civil aircraft, some high-risk subjects in flight and subjects that require evaluating maneuverability and stability under specific meteorological conditions need to use simulator instead of real aircraft. Therefore, it is necessary to research on engineering simulator fidelity evaluation method and process based on airworthiness test requirements. Based on high-risk subjects, such as duel-engine failure, firstly this paper will study the relevant airworthiness provisions and MOC8 test method. Secondly, this paper will analyze the requirements of dual-engine failure subject on the software and hardware of the engineering simulator, and study the fidelity evaluation process and method. Finally, the test results are analyzed and summarized to prove that it conforms to the airworthiness regulations. The research method and results in this paper has been successfully applied to one large civil aircraft, which effectively supports the MOC8 test, and provides compliance evidence for aircraft certification. Meanwhile, the results can also be extended to the subsequent aircraft simulator test, and support the airworthiness certification.