Static test and finite element analysis of high strength cold-formed thin-walled channel flexural members with three types of stiffeners in the flanges and the web were conducted respectively to investigate the mechanical properties and design method of G550 high strength cold-formed thin-walled channel flexural members. The results showed that stiffener type had a significant effect on the member's bending strength and buckling modes. V type stiffeners in the flanges could increase the bending strength more significantly than V type stiffeners in the web. The change law of the bending strength was related to the buckling mode. Based on the existing direct strength method (DSM) formulas as standard, the revised DSM formulas of high strength cold-formed thin-walled channel flexural members were established according to finite element analysis results.