Frequency interference repairing is an effective method for maintaining the normal function of a communication link. The combat effectiveness of the system mainly depends on the support networks and correlative weapon equipment, in which the influence factors have uncertain information. To solve the problem of combat effectiveness evaluation for frequency interference repairment system, the grey hierarchy method was used. The efficiency evaluation index system was analyzed and established, on which basis a grey hierarchy evaluation model was built up. The result of the examples verified the effectiveness of the method and the rationality of the model.