Experimental work on the flexural capacity of concrete shear walls under a strong earthquake was conducted to improve the measurement accuracy of the flexural capacity of concrete shear walls. The study samples were chosen as one concrete shear wall contrast specimen and three test specimens, and the vertical load and horizontal load were applied to simulate the strong seismic intensity. After completing the preparatory work of the test, the separated finite element model was established. In the finite element model, the plastic damage analysis of concrete was completed by calculating the elastic-plastic stiffness of concrete under compression and tension. Based on this, it calculates the flexural capacity of the concrete shear wall. The finite element model was applied to the three test specimens to carry out the simulation test. The simulation results showed that the load-displacement curves of the three specimens are similar to the actual displacement values after a serious earthquake, and the error between the test result and the actual value is less than 2%, which means that the experimental testing method has some viability and shows that the numerical simulation results are accurate.