New full hall scaffolds with pulley-clip style formwork support system is adopted in the concert hall of Changsha. This paper presents the concept of the complete equivalent initial imperfection according to the characteristics of too many influential factors on the high formwork supporting frame，then makes the complete equivalent initial imperfectione equivalent to assumed equivalent horizontal load in order to ensure the safety of the frame. At the same time, it gets a three-dimensional model by the general finite element software ANSYS 10.0. Based on the results of experiment and finite element analysis, it gets the recommended value of assumed equivalent horizontal load. The study on the high formwork supporting frame with pulley-clip style provides some reference for other similar projects.