The approach of network modeling and structure optimization for technology system of systems was researched to solve the problems of reusability and redundancy which are key properties of the development and management of weapon technologies. Abstracting weapon technologies as nodes and abstracting technology relationships as sides, the network modeling approaches based on the description property framework of weapon technologies and the analysis of technology relationships were proposed; three typical approaches of the network community detection were applied to cluster the weapon technologies and the optimization method of technology clustering was generated by comparing the evaluation index of this three approaches; at last, the weapon technologies which are the most influential factors to the redundancy of system were identified at the basis of the centrality measure of weighted networks. A case which includes 235 laser weapon technologies was studied to validate the efficiency of the proposed approach and to summarize the structure optimization method of the system.