Abstract: To study in detail the property on compression-bending of square steel tube filled with steel-reinforced high-strength concrete, the authors have developed a nonlinear analysis of computer program based on theory of the composting method and limited strip unit method. The calculated results of the program agreed well with experimental results. In addition, the influences of slenderness ratio, stirrup ratio and steel-reinforced ratio are also analyzed. Through analyzing the calculated results, a readily formula is obtained. Numerical results for typical members show that the method is simple, efficient and accurate.