Abstract: A monolithic coupling approach to solve the fluid-structure interaction (FSI) problem is presented. The consistent coupling equation is derived from the whole control equation for FSI; also, the pressure Poisson equation (PPE) for FSI is derived. The solution of whole coupling system is gained by solving the PPE and the consistent coupling equation. The approach presented can decrease the degree of freedom (DOF) of solving equations because it does not require solving the whole control equation. The time integration is based on the algorithm of predictor-multi-corrector, which can decrease the numerical error compared with the traditional loosed coupling method. To demonstrate the performance of the proposed approach, an idealized aneurysm model was constructed and the proposed method was employed to perform the FSI simulation of physiological blood flow in the aneurysm model. The results show the validity of the proposed numerical approach.