In order to evaluate the degree of which weaponry improves combat effectiveness, researched the contribution of the certain type of radar in the anti-missile early warning system. According to the radar performance and the task correspondence relation in the anti-missile early warning system, the definition of equipment capacity improvement contribution rate was given. The contribution rate evaluation index system was improved by establishing the anti-missile early warning system. The article proposed the calculation method that equipment individual index capability improvement contribution rate and different types of index capability. Finally, the simulation result verified the rationality of the solution.