Aiming at the problem of combat capacity evaluation method of single conventional missile forces, combined grey whitening weight function and entropy weight method, and evaluate combat capability. According to establishing evaluation index system principles, establish the conventional missile forces combat capacity evaluation index system, adopt grey whitening weight method to evaluate combat capacity. Based on real problem background, improve whitening function, and put forward combat capacity process. The model evaluation result shows that the method can reduce the influence of subjective factor, and makes the evaluation more scientific, effective and reliable.