Experimental researches of one 1:6 scale steel truss reinforced concrete (STRC) transfer beam were carried out to investigate mechanical performances of a transfer beam under vertical loads in an actual tall building. The development of crack along the beam, strains of reinforcements and steel truss, and the force transference mechanism of the deep beam were analyzed. Experimental results showed that the bearing capacity and rigidity of the STRC transfer beam are significantly enhanced compared with normal RC transfer beam. The strut-and-tie force transference mechanism is formed in the STRC transfer beam and fully made use of by the STRC transfer beam. And results verified that the shortest and most direct force transference path can be achieved to transfer upper loads.