Objective To study the causal factors of dispatcher errors quantifiably,analyzing the grey correlativity and validating its reliability so as to control dispatcher errors.Method Firstly the article classifies unsafe events in flight dispatch using D.A.Wiegmans human factors analysis and classification system,and then analyses grey correlativity using grey relativity theory.Result The Order of the main factors causing dispatcher errors is organizational influences,unsafe supervision,precondition for unsafe acts,and unsafe acts.Conclusion (1) The results using grey relativity theory are basically in accordance with the results of Shappels reports; (2) In the level of unsafe acts,the order of casual factors involved dispatcher is skill-based error,decision-based error,and violations; (3) In the level of team cooperation,unsafe events caused by ineffective team communication and coordination cover the largest proportion; (4) In the level of organizational influences,inadequate supervision,supervisory violations and resource management cover larger proportion.