As important member of aviation operation control, flight dispatchers' workload intensity has an important impact on the benefit of airlines. According to the improved doratask method， research on the workload of flight dispatchers, and the flight release process is divided into 13 work processes. The analytic hierarchy process is applied to evaluate each work content under different weather conditions, so as to obtain the difficulty coefficient of each work, and finally realize the evaluation of the workload of a flight dispatcher releasing an aircraft.