Abstract: Based on softened strut-and-tie model, shear mechanical model and calculating method of steel truss reinforced concrete (STRC) deep beam are developed. Through analyzing the mechanical model, the contributions of shape steel, concrete, stirrups and web reinforcements, to the shear strength of STRC deep beam are determined with consideration of softened effects of concrete. Then computer programs are developed to compute the shear strength of the STRC deep beams, good agreement is achieved between the theoretical predictions and the experimental results, which verified that the shear mechanical model and calculating method are accurate enough to predict the shear strength of the STRC deep beams.