The invention discloses a method for treating reinforcing steel bars at cross-shaped steel reinforced column and beam joints on the basis of BIM (building information modeling). The method has the advantages that parameterized BIM models are built, the lengths of supporting plates of cross-shaped steel reinforced columns are constrained by the BIM in advance, accordingly, the supporting plates can be accurately positioned, and a condition that main reinforcing steel bars are collided with the supporting plates can be prevented; the setting-out of longitudinal beam reinforcing steel bars at column and beam intersections is simulated by the aid of the BIM, processes for treating each beam reinforcing steel bar are determined, beams with the weld lengths meeting requirements are welded on the supporting plates and connecting plates, the reinforcing steel bars with large diameters penetrate holes of web plates, and the beam reinforcing steel bars can be directly set out by site staffs according to the models; the beams, the columns and steel ribs can be simulated by the aid of the BIM in advance, disclosure can be carried out on teams and groups, the reinforcing steel bars can be directly placed and welded according to the models during site construction, accordingly, the work efficiency can be improved, wastage of the reinforcing steel bars can be reduced, the construction progress can be accelerated in sites, and the quality of the steel reinforced columns can be improved.