As an important component connecting and sealing the high-pressure fluid in the hydraulic pipeline,the reliability and stability of the aviation pipeline fittings are critical.In order to better understand and analyze the material parameters influence on sealing state of aviation pipeline fittings,a multi-scale finite element contact model was established based on the actual rough surface of pipeline fittings,and the multi-scale model was used to study the influence of the material properties on the sealing state of pipeline fittings.The results show that the multi-scale model can accurately reflect sealing contact state.When the yield strength of the ferrule material is less than that of the pipeline material,the change in the sealing contact area of pipeline fittings is relatively small,and the sealing contact pressure value of the sealing area of pipeline fittings increases with the increase of yield strength.When the yield strength of the ferrule material is greater than that of the pipeline material,the sealing contact area of pipeline fittings decreases,and the corresponding sealing contact pressure distribution of pipeline fittings does not form a good sealing state.Therefore,in order to obtain the better sealing state of pipeline fittings,the yield strength of ferrule should be close to that of pipeline.