The invention relates to a multi-core multi-mode optical fiber, comprising a plurality of core layers and a common outer cladding, characterized in that the number of the core layers is 2, 4 or 8, and each core layer is equally spaced along the circumferential direction , the spacing between adjacent core layers is 38-60 μm for 2 core layers, 38-48 μm for 4 or 8 core layers, and the inner cladding layer and the sunken cladding layer are sequentially coated from the inside to the outside of each core layer, forming a multi-core homogeneous and more Mode fiber, the core layer refractive index profile is parabolic, α is 1.9~2.1, core layer R1 is 12~20μm, core layer Δ1max is 0.7%~1.7%, inner cladding layer width is 0.5~2.5μm, Δ2 is ‑ 0.4%~0.0%, the unilateral width of the sunken cladding layer is 3~7μm, Δ3 is ‑0.7%~‑0.9%, and the common outer cladding is a pure silicon dioxide layer. The invention can not only support multi-mode transmission in the wavelength range of 850nm to 950nm and single-mode transmission in O-band / C-band, but also can optimize the optical fiber structure and viscosity matching to reduce attenuation, so that the crosstalk of the optical fiber, the macrobend and the microbend of each channel can be reduced. The comprehensive performance such as loss is at a good level.