The invention discloses a pair of polish rod calibers and belongs to the field of petroleum. The polish rod calibers comprise a first caliber body, a second caliber body intersecting with the first caliber body at the intersection and a shaft suede for movably connecting the first caliber body and the second caliber body at the intersection, wherein the front end of the first caliber body is curved, and the front end of the second caliber body is curved; a first locking mechanism is connected to the inner side of the rear end of the first caliber body, and a second locking mechanism is connected to the inner side of the rear end of the second caliber body; the first locking mechanism and the second locking mechanism are arranged in corresponding positions; a spring is connected between themiddle portion of the first caliber body and the middle portion of the second caliber body. According to the polish rod calibers, the first locking mechanism and the second locking mechanism are arranged on the inner sides of the rear ends of the first caliber body and the second caliber body, so that a polish rod is clamped with less effort in the process of replacing packing; the spring is arranged between the first caliber body and the second caliber body, and the polish rod can be removed from the calibers with less effort.