Abstract: To establish a contact mechanics model of rough surface with better accuracy, the fractal contact mechanics model considering asperity's deformation properties, fractal theory and friction effect was established from micro perspective based on base length. Using other contact models of rough surface and experiment data as references, the proposed model was investigated. The relationship of fractal dimension, contact force and real contact area was studied by using numerical simulation analysis. The results indicate that the force increased with the increase of fractal dimension to maintain a certain real contact area when the characteristic length scale was fixed. Real contact area increased with the increase of force when fractal dimension and characteristic length scale were fixed. Real contact area decreased with the increase of fractal dimension when characteristic length scale and force were fixed. This model provided a foundation to research friction, wear and lubrication of rough surface.