Abstract: Considering the complex geometry shape and load distribution of a propeller, this paper investigates the accurate solution to their strength checking problems. First, the CFD method of unidirectional fluid-structure coupling and the finite element method are used to calculate and analyze the structural strength of propeller; next, by comparing with the document-recommended safety factor, the rationality of the method is verified; then, the proposed method is used to check the structural strength of the designed controllable pitch propeller on the bollard and design conditions, concurrently comparing with the specification check. Results show that this method, compared with the existing strength check specification, has the advantage of providing more information on the structural strength. Specifically, the method is done by first solving the RANS equation and obtaining the hydrodynamic pressure coefficient of the propeller model surface, then dividing the finite element model of the real propeller, and finally interpolating the pressure coefficient to the finite element mesh node and calculating the hydrodynamic loads of the real propeller surface, simultaneously exerting centrifugal force, and solving the maximum equivalent stress and distortion, as well as calculating the safety factor. The method is designed to the strength research of controllable pitch propeller to provide a means of numerical calculation.