A dynamic artificial disc includes: a buffer body an upper cover located above the buffer body, in which the upper cover includes an upper cover sheet, an upper cover protrusion part located at the periphery or near the periphery of lower side of upper cover sheet, and an upper cover combination member located on the upper side of upper cover sheet and/or surrounding above the upper cover sheet for combining with a vertebra above the upper cover and a lower cover located below the buffer body, in which the lower cover includes a lower cover sheet, a lower cover protrusion part located at the periphery or near the periphery of upper side of lower cover sheet, and a lower cover combination member located on the lower side of lower cover sheet and/or surrounding below the lower cover sheet for combining with a vertebra below the lower cover. The upper cover protrusion part and the lower cover protrusion part are formed with a gapped two-layered protrusion part structure in an inside-and-outside-staggered orientation for housing the buffer body in the space formed by the two-layered protrusion part structure. A clearance exists between the upper cover protrusion part and the lower cover sheet. A clearance exists between the lower cover protrusion part and the upper cover sheet, as well.
