The invention discloses a real-time position correction method of a steel rail corrugation string measuring point. The method includes: acquiring an image of a to-be-detected steel rail; performing image contrast enhancement; extracting a rail top boundary line of the steel rail; positioning a laser measuring point; removing image perspective distortion; correcting position of the laser measuringpoint in real time. Whether the string measuring point in the process of dynamic measuring of corrugation is maintained within a rail top middle effective range or not is monitored and corrected accurately in real time, so that accuracy of corrugation measuring data is ensured effectively, and a solid technical foundation is laid for high-accuracy dynamic detection of steel rail abrasion based onlaser displacement.