The invention relates to the technical field of a numerical control rotary table, in particular to a bolt wheel disc structure and a design method thereof. The bolt wheel disc structure comprises a positioning block, a guide seat and a wheel disc, wherein the positioning block is glidingly arranged in the guide seat, and a positioning bulge is arranged on the front side surface of the positioningblock and is trapezoidal; the wheel disc comprises a positioning chuck, the positioning chuck is rotationally arranged by corresponding to the bulge, a positioning groove is formed in the positioningchuck, and the bulge can be clamped into or retreated from the positioning groove. According to the bolt wheel disc structure, the bulge can be clamped into or retreated from the positioning groove, so that the wheel disc is positioned; the bulge is trapezoidal, and after the positioning wheel disc is braked by the positioning bulge, vibration offset of a fixture on the positioning wheel disc during workpiece processing is reduced.