The virtual network node selection protection strategy model did not fully consider the differences of relevant indicators between nodes, and it will result in low security of protection strategy and the simple credibility index. A design method of node selection protection strategy model under virtual network attack was proposed in this paper. According to the different key degree and reliability of each node, the node selection protection strategy was obtained. The key degree of nodes through the node contraction mode was calculated. Moreover, the credibility of node selection was evaluated through the DS evidence theory under the virtual network attack. Then, the security requirements of virtual network were analyzed. On this basis, the protection strategy model was built by the key node selection strategy of trust evaluation. Experimental result shows that the establishment of nodes selected by model can effectively realize the virtual network protection. The higher the user’s satisfaction is the stronger the practicability is.