Aiming to remedy the degradation of underwater images owing to turbidity of mud and sand in the natural river water, and the change of light caused by underwater refraction, an underwater vision measurement method based on radial multi-line structured light is proposed in this study. First, an underwater visual measurement model based on refraction is constructed. When the projector axis is perpendicular to the refracted plane and the light-plane passes through the projected axis, landed light plane is coplanar with underwater ones, which can avoid the underwater calibration processes. The Monte Carlo simulation method is used to analyze the influence of the imaging point errors on the underwater 3D vision measurement model. Next, an interlaced central rotation radial multi-line light mode is designed. Black and white stripes are used as the projection modes to reduce the dependence on the image quality. Measurement stripes are increased, and measurement resolution is improved through central rotations. Finally, 3D topography measurement experiments on the surface of underwater objects are made, in which the influence of turbid water on the edge extraction accuracy, coded light decoding, and 3D vision measurement are analyzed. In the experiment, sediments with different weights are added in a water volume of 1 m×1.2 m×0.8 m, which simulates the natural water environment. The experiment shows that at a measurement distance of 1500 mm, the surface of a bottle is measured in clean water, with a plane residual error of 0.95 mm; the plane residual errors are respectively 1.93 mm, 5.43 mm, 21.43 mm in muddy water with 40 g, 60 g, 90 g of sediment. When the amount of sediment exceeds a certain value (such as 60 g sediment in this experiment), the accuracy of fringe extraction deteriorates sharply. The residual error of measurement plane fitting in muddy water with 40 g and 90 g of sediment increases from 1.93 mm to 21.43 mm.