Abstract: Although radiographic inspection has such advantages as high rate of defects inspected. visual readability, etc., it suffers from high intensity of labour and low productivity. To speed up pipeline inspection, γ-ray crawler is developed, By operating the external remote controller, a number of non-destructive activir ties are conducted by the crawler inside the pipeline, including advance, back walking, suspending, locating and exposure. The crawler enjoys a number of advantages over other types of inspector, among them are compact structure, light weight, simple operation and maintenance, high precision of location, qualified film, and low exposure of radiation for opera tors, The paper introduces the development of the crawling device, which has been successfully applied in the construction of Shan-Jing Gas Pipeline Project.