To deeply analyze the stiffness and failure mode of composite beams under the combined action of SMW construction shaped steel and cement soil, the article measured the deflection of steel-cement soil composite beams during the bending process through indoor experiments and simulated the behavior using ABAQUS finite element software. Comparative analysis showed that the friction contact element was more reasonable in simulating the steel-cement soil contact relationship. On the basis of verifying the model, the specific effects of factors such as the friction coefficient of the steel cement soil contact surface and the strength of the cement soil on the stiffness changes of the composite structure were further explored. The results show that the frictional contact element can more accurately reflect the actual contact behavior and has a high degree of agreement with experimental data; The greater the interaction between steel and cement soil, the greater the overall stiffness of the composite beam; Under the same load, the stiffness of steel-cement soil composite beams will increase with the increase of cement soil strength.