In a pumping project of landscaping in the downtown area of Karamay, the welted bifurcated pipes are stressed with high water head, and the main pipes and the branch pipes of them are vertically connected leading to the stress concentration at the joints. In order to solve this problem, we calculated and analyzed the stress using a finite element method. The calculation results show that the Q345C steel and 18 mm wall thickness adopted in 1# welted bifurcated pipe unit met the stress requirements with the increased wall thickness without the reinforcement of a reinforcing plate, whereas both 2# and 3# welted bifurcated pipe units needed the welt of an external single-layer reinforcing plate to meet the stress requirements with the adoption of Q390C steel. The thickness of the main pipes, branch pipes and the reinforcing plate is 28 mm, and the width of the reinforcing plate is 500 mm in these two units. The analysis results indicate that the larger the opening of the branch pipes in each unit are, the less integrated the main pipe is, which leads to the stress concentration at the angle between the reinforcing plates of the main and branch pipes. Meanwhile, because the stress at the weld of the reinforcing plates connecting the main and branch pipes is also large, whereas the stress on the pipe wall is relatively low, it is suggested to improve the quality of the welding as much as possible to avoid local excessive tensile stress. The calculation analysis results can provide some reference for the safe operation of the water supply system project. In order to reduce the construction cost, further calculations should be conducted on the integrated finite element model of the corresponding main pipes and their branch pipes to further optimize the structure and layout of the welted bifurcated pipes.