Abstract: In order to improve the quality, efficiency and management level of ultrasonic inspection of rail welds, the IoT(Internet of Things) and cloud technology have been introduced to realize the upload of scenes and inspection data of each site of ultrasonic inspection of rail welds, and realize the interconnection of different inspection sites through network communication. Ultrasonic testing is fully managed by the management center. In the management center, the scenes and testing data of different testing sites can be downloaded at any time, and cloud computing, analysis and processing can be performed. The system can realize cloud live broadcast, cloud analysis, cloud simulation, cloud storage, cloud summary of different testing sites. It is conducive to timely support and guidance of the inspection site, and improve the quality and efficiency of ultrasonic inspection of rail welds.