Abstract: Based on the Timoshenko and Benscoter's theory, a new spatial thin-walled beam element with an arbitrary open or closed cross section is proposed in this paper, accounting for the influences of shear deformation, flexural and torsional coupling and warping shear stress. With introduction of an interior node to the element, three-node interpolation functions are adopted for bending angles and warping angle to consider shear deformation and warping shear stress, and to avoid shear locking simultaneously. Through a kinematic description of the cross section of a deformed thin-walled beam under loads, the flexural-torsional coupling is included in the displacement and strain equations. In order to verify its accuracy and convergence, some numerical examples are analyzed and their results obtained from the present element are compared with theoretical solutions and numerical solutions of the commercial finite element software and other literatures. Comparisons indicate that the present element is free of shear locking and more accurate than those beam elements presented in other documents.