H-section tapered beams and columns are widely used in steel structure factory buildings because tapered members can maximize material performance by matching the approximately triangular bending moment diagram. The Technical Code for Steel Structure of Light-Weight Buildings with Gabled Frames (GB 51022-2015), considering the characteristics of light-weight buildings, has made specific provisions for the design of tapered beams and columns, with economy as the primary goal while ensuring safety. Research indicates that major domestic steel structure analysis software adoptes two-dimensional analysis for factory buildings with tapered beams and columns, failing to fully exploit the huge potential of three-dimensional analysis. Based on GB 51022-2015 and PKPM software, this paper briefly presents the analysis methodology for steel structure factory buildings, key points of stability design for tapered members, and analysis examples using mainstream software, thereby proposing a three-dimensional analysis method for factory buildings with H-section tapered beams and columns. Compared with the two-dimensional analysis method, the three-dimensional analysis method demonstrateds broad applicability and high operational efficiency, while also emphasizing the necessity and urgency for users to master knowledge of steel structure stability theory.