Abstract: When the autonomous in-pipeline inspection robot is working in super-long submarine oil transportation pipelines, it is difficult to locate the wall-loss defect of pipelines. To solve this problem, a design method of fuzzy controller based on wall-loss defect information is presented and applied to the intelligent controller of the autonomous in-pipeline inspection robot. Through the subsequent simulation experiment and the field test of the robot prototype, the intelligent controller is proved to be reliable and stable. And it can achieve precise location, and meets the technical requirements for the inspection robots on accurate defect location of super-long submarine oil transportation pipelines.