The invention discloses a lane line extraction and recognition method based on machine vision. The method comprises the following stepos of collecting image video.; taking image calibration area segmentation and a weighted average method as a grayscale processing algorithm of an interested area, performing smoothing processing on an image by using median filtering, achieving lane line edge detection, image binarization processing and lane line framework extraction by using a canny operator, achieving lane line extraction and identification by using Hough transform based on priori knowledge, combining with the angle range of lane lines and the lateral distance of the lane lines as a screening criteria to eliminate a large number of interference lines during driving and finally achieving accurate extraction of the lane linesd. Accurate and effective extraction of lane lines can be realized, and the early warning accuracy of lane departure is further improved.