High-fidelity models can better meet the increasing requirements of contemporary flight dynamics simulation, making the assurance of their credibility a crucial issue. The credibility assessment of a simulation system must be conducted through Verification, Validation and Accreditation (VV&A). Main validation methods are systematically analyzed. The specific implementation process of a high-fidelity flight dynamics model is investigated from three dimensions: validation items determination, simulation experiment design, and results validation. Model refinement is guided by simulation results analyses involving basic performance parameters, aerodynamic coefficients, and dynamic performance parameters, which provides reference for the validation and optimization of other simulation systems. It also supports the comprehensive application of validation methods and the acquisition of output data from simulation models.