In order to enhance the efficacious operation of the air traffic control system，a quantitative model was established by focusing on the individual load of controllers. Tests were designed to collect pre-service and post-service data on various indicators from 16 area controllers in the front line. Sensitive variables were selected to describe individual loads based on changes in test data. A comprehensive assessment index system was established that included three dimensions: psychological perception load，physiological reaction load，and mental workload. The controller individual load index model was developed. The optimal weights of the individual load index were determined by the the entropy-critic combination weighting method. The quantitative model of the controller's individual workload was finally derived. Further K-Means clustering analysis was performed based on the controller's individual load composite index. There were evident discrepancies in the workload changes of the controllers due to different individual postures. The results indicate that the post-post individual workload changes of the controllers could be classified into three distinct groups. The first group，comprising 50% of the total number of controllers，exhibited the smallest post-post individual workload growth. The second group，accounting for 43.75% of the total number of controllers，exhibited a moderate post-post individual workload growth. The third group，comprising 6.25% of the total number of controllers，exhibited the largest post-post individual workload increase. These findings align with the instructor's ratings of controller competence.