When the controllable pitch propeller is in service,the seal of the propeller hub is realized by the O-ring. It is very important to study the controllable leakage of the hub seal to guide the assembly process design and extend the serv- ice life. The leakage rate equation was derived based on the O-ring micro-contact and leakage channel model. ABAQUS was used to achieve the three-dimensional finite element simulation on the seal of the controllable pitch propeller hub. The influence of different parameters on the sealing performance of the hub was analyzed such as the leakage rate,with corre- sponding process design directions. The influence on the parameters based on the improved composite grey relevance was sorted in order. The results show that the sealing performance is affected by the combination of the roughness,compressibil- ity,rubber hardness as well as the medium pressure. The leakage rate is increased instantaneously with the increase of roughness,decreased with the increase of compressibility and increased with the increase of hardness. The leakage rate is first increased then then decreased with the increase of the medium pressure. The hardness exerts the greatest influence on the maximum Von Mises stress and the contact pressure,followed by the compressibility,while the medium pressure has the greatest influence on the seal leakage rate,followed by the roughness. The accuracy of the model and simulation result was verified by experiments,which provides support for the hub seal design and installation of controllable pitch propeller.