Abstract: A system for measuring the volume scattering function of water with particles was built, helping the laser and the detector to avoid the shading of each other that causes the reduce of detection angle. A set of double-periscopic optical system was used to separate the detection plane of scattering plane from laser exiting plane, thus the shelter of the laser source was minimized. What's more, as the transmission light was exported from the system, the scattering light of water container was avoided so that the precision of backscatter measurement was promoted. The prism for exporting underwater light was designed according to the manufacturing techniques and by which the scattering measurement equipment was designed to measure the scattering light ranges from 3° to 178°. Next, according to the structure of the system and the principle of optical transmission in water, data rectifying methods was designed to rectify the deviation of measurement optical distances and light absorption. The rectified results were finally compared with simulated results of Mie scattering, the main source of deviation was analyzed and the improvement scheme of the system was proposed.