Abstract: When 3D laser scanning technology is used in measuring coal mine roadway deformation, there are problems of limited effective scanning distance, low density of acquired point cloud, serious lack of details, low measurement accuracy and low efficiency. In order to solve these problems, a coal mine roadway deformation measurement system based on line scanning principle is proposed. The system shoots a light strip image of a light plane projected by a line scanning laser on the roadway's surface through a measurement robot's measurement camera. The line structured light strip center extraction technology is used for light strip images to obtain the light strip center coordinates. The light strip center coordinates are substituted into the light plane equation fitted by the light plane calibration technology. The light strip image point cloud data of the roadway surface under the measurement camera coordinate system are solved. The rotary motor drives the line scanning laser and the measurement camera to rotate synchronously to obtain all the point cloud data of the roadway. The multiple groups of tracking cameras are used to capture the target image on the robot, so as to realize the continuous tracking and measurement of the robot's pose. Combined with the robot pose measurement results, all the point cloud data of the roadway are spliced to reconstruct the point cloud of the coal mine roadway. The point cloud slice is used to process the point cloud of the coal mine roadway to realize the rapid measurement of coal mine roadway deformation. The experimental results show that the measurement error of the system is less than 7 mm. The system has the characteristics of simple operation, high flexibility, fast measurement speed, wide measurement range and high measurement precision.