Based on a series of test results of six two-span prestressed steel-concrete continuous composite beams and a general finite element program MSC.MARC(2005r2) as a platform, a fine finite element model is proposed to simulate the whole nonlinear mechanical behavior of prestressed continuous composite beams, and the detailed process of element selection, material modeling and overall assembly is given. Based on the elastic-plastic constitutive model, the finite element analysis can fully consider the material nonlinearity and geometric nonlinearity, reflecting the internal force change, slip effect, internal force redistribution, stress distribution, curvature distribution and plastic hinge formation in the whole process of structural stress, and deeply revealing the stress mechanism and characteristics of prestressed continuous composite beams. The calculated results of the model agree well with the measured results and the theoretical analysis results, and show good numerical characteristics. The model in this paper has high precision and wide applicability for the fine analysis of prestressed continuous composite beams, and provides a powerful tool for studying the mechanical performance of prestressed continuous composite beams.