The computational fluid dynamics(CFD) method is used to simulate numerically the hydraulic characteristics of a marine propeller under reverse bent and twist.The hydraulic parameters such as thrust coefficient,torque coefficient and open-water efficiency etc,are acquired and compared with the experimental results.Both agree with each other fairly well.The detailed distribution of the 3-D flow field obtained from the simulation can be used to analyze the operation performances of the propeller under reverse bent and twist.The conditions of the tip and trailing vortices.The layer mesh,which is referred to as "semistructured"mesh,is used in the vicinity of the propeller surfaces to meet the requirement of boundary layer calculation,while the unstructured mesh is adopted in the flow domain outside the boundary layer.This mesh arrangement is beneficial to raise the calculation accuracy.