Abstract: At present, the work of railway lines patrol inspection is still completed by the staff. The manual detection method is time-consuming, labor-intensive and low efficiency, and it is difficult to complete the railway line detection in harsh environments such as geological disaster areas, cliffs and bridges. In order to improve the efficiency of railway lines patrol inspection and meet the needs of the inspection in harsh environments, this paper built a railway lines patrol inspection platform based on unmanned aerial vehicle(UAV), real time kinematic(RTK) measuring instrument, gimbal, camera and other equipment for shooting live video of railway lines. Based on the cubic spline interpolation method, a UAV flight path model was established to plan the flight path of the platform. Experiments show that the UAV flight path generated by the UAV flight path model has a higher degree of fit to the railway lines, which proves that the method is effective.