The invention relates to a pipeline crawling robot which comprises a flat robot body (100), and six feet (200) symmetrically connected to the two sides of the robot body (100). Each foot (200) comprises a first joint (210) fixedly connected with the robot body (100), a second joint (220) rotationally connected with the first joint (210) through a first connecting device (240), and a third joint (230) rotationally connected with the second joint (220) through a second connecting device (250). The pipeline crawling robot has reasonable six-foot structural design, the robot can be allowed to pass through obstacles such as check valves and butterfly valves under the cooperation of different gaits, the function of freely walking on complex pipelines is achieved, and the robot can pass through turning pipelines; and a large amount of space is reserved on the flat robot body, expansion type tools can be loaded for achieving more functions, for example, a mechanical arm can be loaded for picking falling objects and an electric welding machine can be loaded for welding, and the application range of the pipeline robot is greatly enlarged.