The pipe curtain pre-assembly technology, as a new type of underground shallow-buried excavation method, has gained increasing attention and development due to its excellent safety and practicality. However, there is a lack of comprehensive and systematic research on its mechanical properties, especially in the aspect of bending performance. To further explore the mechanical properties of the pipe curtain pre-assembly structure, two bending components were designed for two-point loading tests. By treating the welded reinforcing bars in the specimen as steel supports between the precast structural steel plates of the steel tube and setting the steel struts as the parameter, the bending performance of the pipe curtain pre-assembly structure was tested and studied. In order to fully investigate the influence of the steel supports on the bending performance of the pipe curtain pre-assembly structure, the finite element software was used to establish the finite element model of the pipe curtain pre-assembly structure components. By comparing with the test results, the correctness of the finite element model was verified. Based on this model, the influence of the diameter and position of the steel struts on the bending performance of the pipe curtain pre-assembly structure was analyzed. The research results show that the firm welding between the steel struts and the steel curtain can effectively prevent the separation of the steel plate from the concrete, improving the mechanical performance of the test specimen; the diameter of the steel struts has a significant impact on the bending bearing capacity of the test specimen; the position of the steel struts has a significant impact on the bending bearing capacity of the test specimen. In actual engineering, the steel supports should be set within the range of equal sections and at positions close to the sudden change in the section height.