To address the demands for enhancing the efficiency of air traffic management and optimizing resource allocation in dynamic airspace environments, a quantitative assessment method for air traffic controllers’ work efficiency based on the fusion of multi-dimensional workloads was proposed. By analyzing the dynamic coupling mechanism between control efficiency and workloads, a four-dimensional evaluation index system including communication, surveillance, operation, thinking, and emergency handling loads was constructed, and the emergency handling factor was incorporated into the quantitative analysis framework for the first time. The entropy weight and analytic hierarchy process combined weighting method was adopted to determine the comprehensive subjective and objective weights of the indicators, and GMM (Gaussian mixture model) was improved based on BKA (black-winged kite algorithm) to establish a hierarchical assessment model for control work efficiency. Empirical evidence based on the video and audio data of the civil aviation air traffic management position vocational skills competition in China shows that the optimized BKA-GMM model can achieve precise classification, with accuracy and silhouette coefficient increasing by 7.08% and 9.82% respectively compared to the traditional GMM. This effectively solves the problem of quantifying control efficiency in dynamic airspace environments and provides a theoretical basis for accurately identifying control bottlenecks and optimizing resource scheduling.