For the online measurement of size deviation in industrial pipelines, this paper proposes a pipe diameter measurement method integrated with multigroup biocular visual system. This method uses image acquisition, 3 D reconstruction and coordinate fusion through multiple laser markers projected on the pipeline measurement section, obtaining dimensional parameters such as outer tube diameter and ellipticity by ellipse fitting. This method realizes the automatic matching of feature points through the affine distance transformation algorithm, and adopts the optimized point cloud registration algorithm with normal vector constraints to ensure the accuracy of coordinate fusion. To verify the feasibility of this method, a multi-group binocular visual experiment system was constructed on three pipelines with nominal external diameter of 285, 299 and 325 mm. The experimental results show that the relative error of the systematic measurement is in the ±0.570% range, with the maximum standard deviation of repeatability of 0.551 mm and the longest measurement time consumption of 1.5 s. The method and system basically meet the needs of industrial pipeline online detection, and have good application prospects.