Aiming at the problems of low positioning accuracy, poor positioning effect and low positioning performance in the center positioning process of the current algorithm, a linear positioning algorithm for the spot center of laser welding pool image is proposed. Firstly, the laser molten pool image is processed by denoising, interference suppression and information enhancement, and the image features are extracted according to the processing results. Secondly, Hough transform method is used to transform the image characteristic parameters to complete the extraction of laser spot center information. Finally, the linear positioning of the laser spot center is realized through the extracted information. Experimental results show that: when the algorithm is used to locate the spot center, it has high positioning accuracy, good positioning effect and strong positioning performance.