Abstract: It is much more difficult to solve the problem of optimizing the operation scheme of a gas pipeline network with cyclic structures than that of a tree-shaped pipeline network. Herein, the flow rates of the pipeline sections on cyclic structures, the number of operating compressors in the compressor stations and the outlet pressure of the compressor stations were used as the decision variables. The minimum energy consumption required for the operation of pipeline network in unit time was used as the objective function. Meanwhile, constraint conditions were comprehensively considered, including the hydraulic and thermal characteristics of the pipeline section, the flow balance at each node of pipeline network, the allowable variation range of the nodal pressure, the operating characteristics of compressor and the allowable operating range. Then, the mixed integer nonlinear programming(MINLP) model was established for the optimization of the steady-state operation scheme of the gas pipeline network with cyclic structures under the premise of knowing the topology, basic parameters, flow rates at gas input and output points, configuration and characteristic curves of compressor units and other parameters of the gas pipeline network with cyclic structures. The model was solved by the algorithm of coupling the branch-and-bound method and the primal dual interior point method. The effectiveness of the model and algorithm was validated based on XQDS pipeline network, and the steady-state simulation of the optimized operation scheme of pipeline network was performed with the TGNET software. Conclusively, the optimization model and algorithm are applicable to the gas pipeline networks with arbitrary topology and could provide new ideas for the centralized scheduling of large-scale and complex gas pipeline networks in China.