Abstract: It was designed an experiment on semi-rigid horizontal force joints of pulley-clip supporting frame through three groups of specimens.By the analysis of experimental phenomena and data as well as the comparisons with joints rigidity of steel tubular scaffolding,following conclusions were obtained: the joints of pulley-clip supporting frame are typical semi-rigid connections,its semi-rigidity is little affected by the different erection distances; the fluctuation of initial connection stiffness of joints is slightly large,when the joint moment is lower than the 20 percent of the control moment; but with over 20 percent of the control moment,the connection stiffness tends towards to be steady; the connection stiffness of the three groups of specimens is equivalent to that of steel tubular scaffolding with tightening torque of 40 Nm,and the stability and erection quality of pulley-clip supporting frame is better than the traditional steel tubular scaffolding．