Abstract: With the accelerating of pipeline construction and the increase of pipeline mileage in China, pipeline detection, maintenance and operating security are research focuses recently. This paper compares the advantages and disadvantages of the seven major in-pipe robots and their application environments and systematically analyzes research status of in-pipe robot technology at home and abroad. It analyzes speed control and positioning control, which are the two core technological difficulties of oil and gas in-pipe robots needed to be solved urgently, and points out the research emphasis of oil and gas in-pipe robots in the future should focus on constructing flexible and reliable mechanical structures, realizing real-time and stable control systems, and putting forward new energy supply technology, etc. What reviews and analyzes in this paper has some reference value to research of oil and gas in-pipe robot.