T⁃shaped multi⁃branch pipeline is a kind of T⁃shaped pipeline with complex multi⁃branch structure, which is now widely used in the research of two⁃phase and multi⁃phase flow.In this article,the fluid simulation tool Fluent was used to simulate the oil and gas two⁃phase flow in the T⁃shaped pipeline at different times with obtained the oil and gas separation characteristics of each branch and the mass flow data of the inlet and outlet.The results indicate that, when the oil and gas two⁃phase mixed infusion flows through the T⁃shaped pipeline, the phase distribution of the oil and gas two⁃phase in the pipeline is uneven due to the effect of gravity.With the increase of time, the gas⁃outlet at the top is mostly gas, while the oil⁃outlet at the bottom is mostly liquid, thus achieving a initial separation of oil and gas. T⁃shaped pipeline with different branch pipe heights are selected for simulation, and the characteristics of oil⁃gas separation phenomena are analyzed. Then select different inlet velocity of T⁃shaped main pipe to observe the effect of inlet velocity on oil⁃gas separation.Finally, by analyzing the turbulent vortex structure and flow field characteristics in the pipeline, the turbulence coherent structure shows the characteristics of regularity and repeatability under the same structural parameters, and the influence of branch pipeline on flow pattern and turbulence vortex.