Air traffic management (ATM) system is an important part of the air operating system, and its safe operation directly affects the aviation safety. According to the characters of ATM, this paper establishes an index system of ATM system safety evaluation. Considering the quantitative indices are interval grey numbers and the qualitative indices are language values, the safety evaluation method based on the grey evidence theory is presented. Finally, the feasibility and validity of the evaluation method is demonstrated by an ATM case study. [ABSTRACT FROM AUTHOR]