The utility model provides an instrument is changed in power ball O type area, the change instrument is including the operation ring sum guide cone body, guide cone body main part is round platform form or coniform, and the big footpath of the guide cone body is held and is equipped with the connecting portion that are the rotating body form, the big footpath end of connecting portion and axle setting of the guide cone component parts of an entirety and connecting portion links to each other with the big footpath end of the guide cone body, and the diameter of the big footpath end of the diameter less than or equal to guide cone body of the big footpath end of connecting portion, the diameter of the big footpath end of connecting portion match with the diameter of the big footpath end of spherical crown portion, and highly the matching of the height of connecting portion and spherical crown portion, operation ring is including operation ring body, and the upper portion of operation ring body is used for the cover to establish O type area, the operation ring this internal be equipped with with the mating holes of connecting portion looks adaptation. The simple and convenient exquisiteness of this instrument can make things convenient for the O type of installing fast area, has alleviateed maintenance man worker's operation intensity, has improved work efficiency effectively.