Abstract: To investigate the web shear behavior of single-box multi-cell composite box with corrugated steel webs (CGCSW), the web shear stress distribution is studied in this paper. Finite element models of single-box CGCSWs with two or three cells are established, which are verified by elastic loading experiments of scaled specimens. The shear strains of different webs are obtained under different kinds of lateral symmetric and eccentric loads, including concentrated loads, distributed line loads and distributed plane loads. The distribution features of the web shear stress and the causes are analyzed. The results show that the shear strains in different webs are obviously different under concentrated loads and distributed line loads because the acting positions are different. The ratio of the web shear stress and section average shear stress may exceed 2.0 under symmetric loads, and may exceed 4.5 under eccentric loads. Under concentrated loads and distributed line loads, uneven shear stress distribution in the webs should be considered correctly in structural analysis. Under distributed plane loads, the shear stress may be considered to be equal in all webs. According to the features of the shear stress distribution, it is proposed that the calculation of web shear stress should include flexural shear stress, torsional shear stress and shear stress caused by local section distortion.