Abstract: Objective Collagen fiber damage in the articular cartilage is considered to be a manifestation of early joint degeneration. Methods In this paper, two-dimensional numerical model of fiber-reinforced porous viscoelasticity was established, considering the relationship of fiber distribution, elastic modulus, porosity and permeability with cartilage depth. The maximum by studying influence of the local fracture of the fiber bundle,the progressive fracture from the surface and the fiber bundle size on the mechanical properties of the cartilage. Results The results showed that the maximum principal strain of the matrix occurred at a position in the middle layer of the cartilage, about upper 1/3 of cartilage, which was not affected by fiber breakage mode and fiber bundle size. The strain value of cartilage with thicker fiber bundles decreased.. Conclusions The middle layer of cartilage was prone to mechanical damage.The thicken fiber bundle could reduce the maximum principal strain of the matrix. Once the fiber bundle broke, the maximum principal strain of the matrix of the cartilage with thicker fiber bundle was larger, which made the cartilage damage evolution easier. The results of this study could provide reference data for clinicians to guide the rehabilitation project of patients with early cartilage injury.