Abstract:The deep-water multifunctional pipeline working tool is an underwater special working tool, which can complete six functions: removing the anti-corrosion layer on the pipeline surface, drilling, cutting off pipeline, chamfering inside/outside the pipeline end and removing the pipeline weld in one clamping. During clamping, the centering error exists between the cutter rotating center and the pipe center, which leads to the dynamic error of chamfering depth during the pipe end chamfering and deburring operations,and the cutter punching phenomenon is occurred when the error is large. In order to solve the problem, based on the principle of threepoint circle fixing, a measurement method was proposed to automatically measure the deviation of the pipe’〖KG-*2〗s center of rotation relative to the cutter disc through three sets of laser distance sensors, and a mathematical model of the dynamic error of chamfering depth at the cutter position was deduced,and the performance test of the prototype land-based automatic control of chamfering depth was completed. The test verifies the validity of the centering error measurement method and the control of the chamfering depth error, and the key technical problem that the great change of draft depth during the pipe end chamfering operation and the cutter punching phenomenon when the machine is working underwater is solved. This study provides technical supports for the safe underwater operation of the machine.