The grey AHP effectiveness evaluation problem of electronic warfare command and control system (EWCCS) under complex electromagnetic environment is investigated. First, the evaluation hierarchy structures of EWCCS under complex electromagnetic environment are put forward and can be classified into target hierarchy, rule hierarchy and scheme hierarchy. Then, the grey AHP Algorithm is given as a preliminary knowledge to evaluate the effectiveness evaluation of EWCCS under complex electromagnetic environment. Finally, an effectiveness evaluation example of three EWCC systems under complex electromagnetic environment is considered by using the grey analytic hierarchy process (AHP) Algorithm, and the grey comprehensive evaluations for the three EWCC systems under complex electromagnetic environment and their grades of the grey comprehensive evaluation are proposed.