<p>Fractal theory is widely used in multiscale contact analysis of rough surfaces. However, it typically extends single-asperity contact behavior to the entire surface via the area distribution law, assuming that all asperities are fully deformed. This simplification fails to adequately describe the actual contact state. To overcome this limitation, this paper introduces a contact ratio and develops a multiscale contact model that can appropriately capture the asperity contact condition. First, a single-asperity elastoplastic constitutive model is constructed with the mean absolute slope (MAS), and the contact ratio is introduced to characterize the contact state. Based on this single-asperity model, statistical extension to the whole surface is realized through the area distribution function. Subsequently, a method for calculating the contact ratio of rough surfaces and an MAS-based truncation contact model are presented. Using the proposed model, the variation of the contact ratio with fractal parameters is revealed, and the effective computational range of the truncation contact model is discussed. Finally, the accuracy and applicability of the model are validated through finite element simulations, comparisons with classical experimental data, and independent compression experiments on scraped surfaces. This study offers a new perspective for advancing rough surface contact theory.</p> Graphical Abstract <p></p>