Aimed at the problem that the tradition effectiveness evaluation method is not suit to the modern Beyond Visual Range (BVR) air combat and combined with the characteristic of command and guide in BVR air combat, a new effectiveness evaluation model of command and guide in BVR air combat is proposed. The model is used to proceed from the analysis of the destination situation of command and guide, and select the three factors angle，distance and energy as the evaluation indexes of the command and guide situation. And then by comprehensively taking the influence of radar detection distance and the airtoair missile shoot distance on command and guide into consideration, the corresponding superiority exponentials are separately established and the weight of each index is confirmed through analytical hierarchy process. Finally an effectiveness function of command and guide in BVR air combat is obtained by use of the weighted synthetic assessment method. The effectiveness of the model is verified by situation results