The invention provides a sealing ring size rechecking device with a rejecting function. The sealing ring size rechecking device with the rejecting function comprises a base, and a supporting frame fixedly connected to the left side of the top of the base. According to the sealing ring size rechecking device with the rejecting function, by arranging the size rechecking structure, four O-shaped sealing rings of different sizes can be measured at the same time, different measurement requirements can be met, and compared with a traditional single measurement mode, the sealing ring size recheckingdevice can adapt to measurement of the four O-shaped sealing rings of different sizes at the same time, different measuring cylinders do not need to be replaced frequently, operation steps are simplified, use is more convenient, meanwhile, the threaded rotating rod is arranged to be in threaded connection with the four measuring cylinders, the measuring cylinders can be contracted, the measuring cylinders can be protected when not used, the surface of the measuring cylinder is prevented from being damaged by external environmental factors, and the measuring precision is prevented from being affected.