The utility model discloses a revolution body centering clamping device with an adjustable diameter. The revolution body centering clamping device comprises a hollow cylindrical plate body and workpiece centering mechanisms. The plate body is driven by a machine and comprises an upper half ring and a lower half ring. The joint of the upper half ring and the lower half ring is provided with a revolution shaft, and the upper half ring can be overturned backwards around the revolution shaft. A locating pin corresponding to the revolution shaft is provided with a clamping bolt and a clamping nut enabling the upper half ring and the lower half ring to be fixed. The workpiece centering mechanisms are centering nuts which are arranged in the peripheral direction of the plate body and enable the center of a workpiece to coincide with the revolution center of the machine. The centering nuts are provided with set screws preventing the positions of the centering nuts from changing. The lower half ring is fixed to an output shaft of the machine through a transition plate. The revolution body centering clamp body is simple in structure, convenient to use and capable of effectively improving machining efficiency.