Recent years has seen the proliferation of various fluid pipe networks in our living and working environments. With the growth in size, complexity and scale, fluid pipe networks are faced with numerous problems like pipe collision and bursting. To prevent these problems, ensure the operation efficiency and save cost, this paper probes into the structure and performance of two fluid pipe networks that backs up each other. Based on topological analysis algorithm, the two fluid pipe networks were converted into topological graphs, and created topological models involving pipe elements and nodes. Through optimization of the models, the author proposed the two-pipe connection mode for the two pipe networks. The optimization strategy was then verified through a simulation application in a tree-shaped water injection system. The results show that our strategy can effectively optimize the two-pipe connection, ensure the operation efficiency and save the network cost. The research findings provide a good reference to the design and optimization of fluid pipe networks in China.