In order to study the bearing characteristics of rough surfaces during the hydroviscous transmission process,the fractal theory was introduced into the friction process of two rough surfaces,the bearing process of asperities in the mixed friction stage and boundary friction stage was analyzed,the bearing model based on the modified M-B model was also established.Through the numerical simulation,the influence of effective area coefficient and fractal parameters on the transmission process was obtained.The calculation results of the modified asperities bearing model were compared with those of M-B model.The results show that the contact load and transmission torque of the asperities are increased with the increase of the contact area ratio,and are increased when increasing the effective area coefficient and fractal roughness parameter.When the fractal dimension is 1.5,the contact load and transmission torque are the smallest and change most slowly with the contact area ratio.In the whole contact area,the area,contact load and transmission torque of the elastic deformation are the largest,followed by the elasticplastic deformation and the plastic deformation is the smallest.Both contact load and transmission torque are decreased when considering the elasticplastic deformation.The correction factor range between the M-B model and the modified M-B model is within 25%,and it is increased with the increase of effective area coefficient and fractal roughness parameter and decreased with the increase of the fractal dimension