Traditional GPS jamming equipment can hardly meet the requirements of the operation against cruise missiles,thus a development scenario of networked GPS jamming system is proposed.The model of the operation loop of GPS jamming equipment cooperating with ground air defense firepower against cruise missiles is established.The capability indexes of nodes and the measurement index of edges are determined,and the operational effectiveness of the system is calculated based on information entropy.The model for calculating the contribution ratio of GPS jamming equipment system is proposed based on the general consideration of the cost and risk factors of equipment development.The application results show that,the GPS jamming equipment can create a large gain on the system operation effect and achieve a high system contribution ratio.Taking the cost and risk factors into consideration,the evaluation result of contribution ratio to system-of-systems is more practical and more significant for decision-making assistance.