Abstract: In order to investigate the shear mechanism of steel reinforced concrete composite beams and further optimize their section shapes, a static experiment with ten full-scaled specimens was carried out. The developments of strain, crack propagation, failure mode, deformation and shear capacity were thoroughly explored and the effects of aspect ratio and section shape (solid and hollow) were critically examined. On the basis of the test results, a proposed truss-arch model, which takes the compatibility of a truss, an arch and steel shape into account, was applied to establish the calculation method for the shear capacity of steel reinforced concrete hollow composite beams. The results indicated that: the specimens with solid section and hollow section both suffered similar failure modes and exhibited similar shear bearing capacities, and the shear bearing capacity decreased with the increase of the aspect ratio. The shear capacity calculated by the JGJ 138-2016 and YB 9082-2006 shows high discreteness. The shear strengths obtained by the proposed method (compatible truss-arch model) agreed well with those from the experiment.