Vertical stiffener joint, a new type of rigid joint between concrete-filled steel square tubular column and H-steel beam, is proposed based on the analysis of construction and features of three types of rigid joints. Force transfer mechanism of the vertical stiffener joint model with only tensile beam flange is analyzed, and based on yield line theory, the formula for calculating the yield bearing capacity of the joint model is presented, which provides a basis for its further research and application in projects.