Abstract: Based on the experimental study on different scaled models of the frame-supported multi-ribbed slab wall beam under monotonously vertical load, it is discussed the mechanical behavior of the wall beam under vertical load. Moreover, the main factors affecting the internal force distribution are studied by means of finite element analysis. According to the theory of elastic foundation beam and quoting the trigonometric series analysis, the internal force calculation formula of the frame-supported multi-ribbed wall beam is put forward, and the internal force correction coefficient in the formula is obtained by regression analysis at the same time. Theoretical analysis and experimental results show that there has strong combination action between the trimmer beam and multi-ribbed composite wall, and the results calculated by the practical internal force calculation formula can be closer to the experimental values.