The invention provides an annular cutting device of a large-section wire, which comprises a coaxial annular gripping mechanism and a cutting mechanism, wherein an annular connecting block is arranged between the gripping mechanism and the cutting mechanism. The device is characterized in that the gripping mechanism comprises an internal ring and an external ring, wherein an annular frame is arranged on one side of the internal ring and internally provided with fixing terminals; the cutting mechanism comprises a movable support and a fixed support which are respectively arranged along the diameter of the cutting mechanism; the movable support is provided with a chuck; a grinding wheel fixing shaft is arranged in a circle center of the fixed support; and the chuck is tangent with the grinding wheel fixing shaft. Compared with the prior art, the annular cutting device of the large-section wire can grip the large-section wire stably and effectively and cut the large-section wire, is simple in structure and convenient to operate, greatly reduces the labor intensity, shortens the working time and improves the working efficiency.