Centralizer and centralizing method

The invention provides a centralizer and a centralizing method, and belongs to the field of petroleum mechanical equipment. The centralizer comprises a body, at least three centralizing slips, a gear and a driving device, the at least three centralizing slips are arranged in the body, one ends of the at least three centralizing slips are connected with the inner side of the body through a first shaft, the side faces of the at least three centralizing slips are meshed with the inner surface of the gear arranged on the body in a sleeving mode, and the gear is meshed with the driving device. A first through hole is formed in the center of the body, and an oil pipe to be centralized penetrates through the first through hole to enter the body. The driving device is used for driving the other ends of the at least three centralizing slips to be folded towards the first through hole through the gears so as to centralize the oil pipe. The at least three centralizing slips of the centralizer can centralize an oil pipe,