The invention relates to a bottom chord open truss type corrugated steel web composite beam, belonging to a bridge support member. The bottom chord open truss type corrugated steel web composite beam is composed of a top-wing concrete slab, a corrugated steel web and a bottom chord open truss type rectangular steel 
pipe concrete. Compared with the steel truss type web composite cross section, the bottom chord open truss type corrugated steel web composite beam adopts the corrugated steel web with high 
shear strength to replace the steel web bar, and has high shear bearing force. The open truss type bottom chord is composed of two parallel rectangular steel pipes and concretes casted in the steel pipes, horizontal supports between rectangular steel pipes, and inclined supports. the bottom chord adopts the steel 
pipe concrete member to overcome the problem that the bottom 
flange concrete of the traditional corrugated steel web box beam and steel truss type web composite cross section needs to set up 
scaffold, support framework and concrete 
casting so as to have large work load, moreover the bottom chord open truss type corrugated steel web composite beam can improve 
crack resistance of structure effectively and avoid crack from being exposed, so that structural endurance can be obviously improved. The bottom chord is an 
open type structure with support connection, and has the advantages of simple structure, convenient and 
rapid construction.