Aimed at the problems of high temperature and severe frictional wear of the mechanical seal end face in the start-stop phase or under some specific working conditions,the change law of contact pressure and temperature rise of the microporous mechanical seal end face considering the roughness effect was investigated to reveal the real contact state of the mechanical seal end face.Based on the fractal theory,a surface contact model between the rough surface of the static ring and the microporous of the dynamic ring of mechanical seals was established based on fractal theory.The numerical calculation method was used to study the effect of microporous on contact pressure and temperature rise of mechanical seal end faces,and the effect of different surface roughness on contact area,contact pressure and temperature rise of mechanical seal end faces.The results show that when the micro-convex body passes through the microporous,the micro-convex body is embedded in the microporous,which makes the peak contact pressure increase at the edge of the microporous,leading to cutting.During the friction process,the position of the highest pressure point is not fixed because of the elastic-plastic deformation of the micro-convex body,which improves the force on the micro-convex body.The microporous reduces the contact area of the seal end face,thus the contact of the micro-convex body is reduced,the pressure extreme point and the temperature of the friction pair of the sealing end face are reduced,and the wear state of the sealing end face is improved.The smaller the surface roughness,the larger the contact area,the more uniform the contact pressure and end face temperature,and the larger the surface roughness,the more serious the risk of end face wear.