Abstract: For symmetrical steel bifurcated pipe with flat floor, the bottom of each pipe joint is at the same elevation, and the water body can be discharged by self-flow during the maintenance of steel pipe, which is convenient for maintenance.However, it is difficult to design its shape by conventional analytical methods, and the efficiency of drawing is low.In this paper, the standard template of symmetrical bifurcated pipe with flat floor was established in CATIA to adapt to the 3D design of different sizes of steel bifurcated pipe.Then taking the steel bifurcated pipe of Deluo Hydropower Station as an example, the ANSYS program was used to analyze the mechanical characteristics of crescent rib steel bifurcated pipe, crescent rib steel bifurcated pipe with flat floor and tri-beam reinforced steel bifurcated pipe with flat floor.The results show that all of these steel bifurcated pipes can meet the stress requirements.Crescent rib bifurcated pipe shows the best stress, but its drainage performance is not good.When the flat bottom steel bifurcated pipe with flat strengthened by three beams, the stress of the strengthening beam and the bifurcated pipe wall is significantly improved.The steel bifurcated pipe with flat floor can not only facilitate drainage maintenance, but also meet the stress requirements, which can be popularized in engineering.