In order to improve the accuracy of modern anti-ship missile weapon system evaluation, an evaluation method based on the combat ring-extension cloud model is proposed. Based on the theory of combat ring, a comprehensive anti-ship missile system operational effectiveness evaluation index system is constructed. The G-1 order relationship method is used to assign weights to the evaluation index system. The extension cloud model method is used to evaluate the operational effectiveness of the anti-ship missile system. And an example verification of an anti-ship missile system against a large surface warship is carried out. The simulation results show that the method has objectivity, accuracy and comprehensiveness.