This is a new rail transit inspection robot. It is mainly used for the routine inspection of the undercarriage of high-speed trains. Currently, the total number of high-speed rail mileage has exceeded 80,000 km, high-speed rail vehicles in operation every day up to 5,000. And the world has been developed and put into use of the intelligent track bottom inspection robot only 5 enterprises. Therefore, every day a large number of human resources into the day-to-day detection work, which also caused an increase in the probability of error. Normally there are 18,000 parts in the mechanical structure under a train and they are all checked every two days. The new intelligent rail transit robot's detection program has covered 200 common fault items and trouble spots on trains, with a processing speed of 20,000 per hour. In particular, the success rate of important fault diagnosis is over 99% . The traditional manual detection, a train under the time is 160 minutes, the need for four professional staff at the same time. As a result, this greatly reduces the human cost and the probability of error. In addition, we designed 32 ultrasonic radars and 6 lidar for the robot, which is the first autonomous bottom inspection robot in the industry. At the top of the arm is a super-high-definition visible-light camera and an infrared camera, with millimeter-scale detection accuracy, that can compare photos of the same fault point with different imaging principles, you can anticipate potential risk problems. The intelligent rail transit bottom inspection robot also provides intelligent management data for daily inspection of high-speed trains.