A laser vision detection method for welding joint assembly quality information parameters of mine explosionproof shell is proposed. Firstly, a set of vision measurement system with camera, grating laser and computer as the core is built to obtain the grating fringe image of the bottom of the shell with welding joint. By analyzing the coupling between the grating fringe and the welding joint, the correlation between the feature points of the grating fringe and the amount of the assembly gap and the amount of the wrong side is obtained. Secondly, the grating fringe in the image is segmented and refined to obtain the coordinates of the fringe contour points. The characteristic point coordinates of the grating fringe are obtained by automatically searching the data of the computer, and the matrix of the feature points of the grating fringe is established. Finally, based on the characteristic point matrix, the algorithm of welding joint assembly gap and error variable is established, and the welding joint assembly quality evaluation index and method based on welding joint gap and error variable are established. The verification results show that the assembly information obtained by the vision measurement system is in good agreement with the manual measurement results, which can replace the manual measurement to realize the evaluation of assembly quality.