The invention discloses a railway line inspection system. The railway line inspection system comprises a coming and going train information acquisition subsystem, a data and fault processing subsystem, a flight control subsystem and a data acquisition subsystem. The coming and going train information acquisition subsystem determines coming and going train information of a railway line and sends the coming and going train information to the data and fault processing subsystem. The flight control subsystem controls the flight track and attitude of an unmanned aerial vehicle and the action of avoiding coming and going trains. The data acquisition subsystem is arranged on the unmanned aerial vehicle, acquires field data of the railway line and sends the field data to the data and fault processing subsystem to be processed, wherein the field data comprises radar scanning data and field image data of the railway line. The data and fault processing subsystem receives and analyzes the field data of the railway line and determines the fault type and generation position. The technical problems that an existing railway line inspection mode is single in means and low in reliability, affects normal train driving and cannot meet the requirements for high-speed railway operation safety can be solved.