The utility model relates to a kava telescopic segment type operation device provided with pressure and a fixed top, which is applied to the petroleum well repairing operation construction with pressure. The utility model is characterized in that the upper part of the cross joint of the well mouth is orderly fixed with a three-flashboard blowout preventer, a lower omnipotence blowout preventer, a cross joint, a telescopic segment and an upper omnipotence blowout preventer. The top part of an upper circular blowout preventer is connected on a beam, and the upper part of the beam is connected with a set of travelling kavas. The beam is connected with the cylinder rod of an elevating liquid cylinder. A set of fixed kavas are fixed on an upper flat roof, and the upper flat roof is fixed at the top of an upright post. The lower end of the upright post is fixed on a lower flat roof, and the lower flat roof is fixed between the three-flashboard blowout preventer and the lower omnipotence blowout preventer. A middle flat roof is fixed on the upright post. The effect is that the fixed kavas are broken away from the blowout preventer set and are fixed at the upper part of the upper flat roof; and the upper flat roof is fixed with the travelling kavas. The defect that the fixed kavas in the telescopic segment type operation device with pressure must adopt sealing mode. The utility model has the advantages that the operation of exchanging kava teeth, and the security and working efficiency of the well repairing operation are improved.