In order to promote the application of composite materials in building structures, a study was conducted on the flexural performance and overall comfort of prefabricated steel-concrete composite stair treads. Six stair tread specimens were tested using a four-point bending test, focusing on the influence of the shear reinforcement and the connection method between the tread and the stringer on the load-bearing performance of the stair treads. The test results showed that compared to angle steel and bolt shear reinforcement, channel steel shear reinforcement significantly improved the load-bearing capacity of the stair treads. Moreover, the load-bearing capacity of the welded specimens was less affected by the shear reinforcement and higher than that of the simply supported specimens. This indicates that welding can be considered as the primary connection method between the steel-concrete composite stair treads and stringers in future engineering applications. To accurately study the mechanical behavior of the stair treads, ABAQUS software was used to model the stair treads. The finite element model accurately simulated the mechanical behavior of the stair treads. Based on the validation of the model accuracy, a comfort analysis was conducted on the overall stairs. The natural frequency of the stairs and the acceleration response under human-induced excitation were within the specified limits, satisfying the comfort requirements for walking. The stairs will not cause any noticeable discomfort during use, meeting the requirements of ergonomics. The test and modeling analysis have proved that channel steel shear reinforcement provided a significant improvement in the load-bearing capacity of the stair treads Welding can be considered as the primary connection method between the stair treads and stringers, and the comfort analysis showed that the stairs met the specified requirements.