In order to reduce the computational complexity of network fault propagation model and improve the accuracy of network fault location, a network fault location algorithm based on hierarchical bipartite graph and the improved differential evolution is proposed, which is suitable for computer network information security management or privacy protection. Firstly, the complete bipartite graph failure model is designed by introducing the hierarchical fault diagnosis concept, and it is used to locate the network fault of the system in three different levels of submodels. Then use different bipartite graph fault propagation models for network fault diagnosis. Finally, through the heuristic idea, combined with the improved differential evolution algorithm to solve the problem, the problem of low fault location accuracy is effectively solved. The effectiveness of the proposed algorithm is proved by simulation experiments. The results show that the proposed algorithm has higher accuracy and less diagnostic positioning time.