Abstract: Traditional integral models find it is difficult to represent steel effects for reinforced concrete structures, leading to the calculation results less informative. Taking into full consideration of steel effects after crack development when define the constitutive relationship can improve the accuracy of the integral model. In this study, both separate and integral models were established. In addition, concrete strength and particle size were considered to accurately define the nonlinear constitutive relation, especially the power transmission capacity of the concrete cracks. Experimental results were used to verify the optimized method. The results were also compared with the calculation of the separate model in terms of cracking strength, crack development process, displacement of monitoring points, and ultimate strength of the structure. Results from both numerical methods match well with experimental results, and the optimized one is much faster. Finally, the optimized method was used to analyze crack development of a reinforced concrete column under earthquake with high accuracy and efficiency.