Provided are a lane line detection method, an autonomous mobile device, and a storage medium. In the lane line detection method, an original image captured by a camera of the autonomous mobile device is acquired, and an ab-channel-based gradient image is calculated according to the original image. Line segments located on edges of lane lines are extracted from the ab-channel-based gradient image, to obtain multiple original line segments. Collinear line segments among the multiple original line segments are cascaded in an iterative manner, to obtain multiple cascaded line segments. Multiple candidate lane lines are generated from the multiple cascaded line segments. Collinear candidate lane lines of the multiple cascaded line segments are merged to obtain lane lines in the original image.