Square steel tube filled with steel reinforced concrete subjected to shear force was simulated by finite element method. Limit value of broken on pure shear, bending-shear and bending were given. Influence of stirrup ratio, steel reinforced ratio, strength of concrete under shear force was also analyzed. Finally, formula for pure shear capacity of square steel tube filled with steel reinforced concrete was proposed by research the calculated results. Calculated results showed that it agreed well with that of corresponding document.