Abstract: Objective: In the research on bottom-opening suspended monorail lines in China and abroad, there is a lack of studies on track beam torsional performance and analysis of curved track beam profile deformation under vertical loads. It is necessary to conduct an in-depth analysis of monorail line track beam torsional performance. Method: Based on the design experiences of suspended monorails in China and monorails in Japan, the structure of suspended monorail PC (pre-stressed concrete) track beam is introduced, and the vertical train loads on structural beams is analyzed. The problems existing in the conventional Vlasov thin-walled beam theory are discussed, and the primary parametric solution for track beam restrained torsion considering the shear strain of the mid-span cross-section is derived. A curved beam model is established using finite element software to analyze the vertical displacement and torque variation at the mid-span cross-section caused by vertical load action when taking values of different curve radius and top plate thickness. Concentrated torsion is applied at the mid-span cross-section, and the stress distribution of various sections in the mid-span right segment of the track beam is analyzed, comparing theoretical calculation and model simulation values.Result & Conclusion: For bottom-opening box-shaped PC track beams with fixed constraints at both ends, the shear deformation should not be neglected when subjected to concentrated torsion at the mid-span cross-section. The influence of shear strain should be considered in the design of such track beams. Increasing the top plate thickness of curved track beams can enhance the overall torsional resistance performance of the beam cross-section. Under vertical static live loads, the torsional angle at the mid-span cross-section increases as the curve radius decreases.