Abstract: In order to improve the accuracy of security risk assessment of wireless sensor network, we proposed a model of security risk assessment of wireless sensor network based on index selection and weighted fusion. Firstly, the index system of security risk assessment of wireless sensor network was established, and some indexes with important contribution were selected by grey relation analysis method. Secondly, according to the correlation degree, the security risk assessment indexes of important wireless sensor network were weighted,  support vector machine was used to fit the characteristics of security risk change of wireless sensor network, and particle swarm optimization algorithm was introduced to optimize the parameters of support vector machine. Finally, the results were compared with other models. The results show that the proposed model obtains better security risk evaluation results than the comparison model. The accuracy of the assessment is more than 95%, and the efficiency of the security risk assessment of wireless sensor networks is improved.

Key words: wireless sensor network, risk assessment, index system, index contribution rate, grey relation analysis method, particle swarm optimization algorithm