The present invention provides a ranging method based on laser-line scanning imaging to effectively suppress interference of extreme weather on imaging. The method includes the following steps: acquiring priori reference images for a fixed laser-line scanning system, including respectively placing reference whiteboards at different distances, projecting line laser beams to the whiteboards, and acquiring the reference images by using a camera; placing a laser-line scanning device in a real scene, causing the laser-line scanning device to respectively emit line lasers at different angles, and acquiring an image at each scanning angle by using a camera; and performing fusion calculation on the acquired scanning image in the real scene and the priori reference images by using a ranging algorithm based on laser-line scanning, and extracting distance information of a surrounding object, to implement environment perception.