Abstract: A kind of modularized prefabricated steel frame with through column and solid-web beam is presented. Global stability of beams with dual-channel combined section formed through the assembly of plates is studied. Firstly, the feasibility of establishment method of the finite element model is proved. Then the effect of bolt pitch on the static performance of beams with dual-channel combined section under different bolt arrangement is analyzed and reasonable bolt pitch is investigated. The influence of beam section height, flange width and thickness, web thickness, beam length, width between double channels, bolt arrangement and load type on the global stability of steel beams is analyzed. The formula for calculating the equivalent bending moment coefficient and the relationship between the elastic-plastic stability coefficient and the elastic stability coefficient are obtained by the fitting method. The formula for calculating the elastic-plastic stability coefficient under different load types are obtained through the equivalent bending moment coefficient and elastic-plastic correction of calculation formula of elastic stability coefficient under pure moment.