Ensuring consistency and validity in flight training assessment proves challenging due to the traditional reliance on instructors' subjective evaluations and the imprecise quantitative criteria for competencies. A novel mathematical model based on the VENN model was introduced to evaluate behavioral indicators displayed during flight training across three dimensions: quantity, frequency, and the outcomes of threat and error management. Transforming the examination of subjects in flight training into a quantitative evaluation of abilities, and combining historical inspection work sheet data, an optimization method for competency evaluation standards was proposed. Finally, the effectiveness of the proposed method was validated using an actual manual flight control skill evaluation as an example. The results demonstrate a significant correlation between the final assessment criteria derived from the algorithm and the ratings provided by instructors, with 83.3% of the samples exhibiting rating consistency and the remaining samples deviating by no more than one level. This suggests that the proposed method adeptly transforms historical checklist information into assessment criteria for competency, offering theoretical support and a new data-driven approach for formulating competency assessment criteria.