Computer-vision-based underwater laser datum line measuring system

The invention, which belongs to the underwater special measurement field, discloses a computer-vision-based underwater laser datum line measuring system for measuring a relative position parameter for underwater structure installation and assisting in underwater engineering building. According to the measuring system, a laser ray generated by a high-power laser is used as a preset datum line and a measuring scale, thereby providing an image feature for computer vision software measurement. An underwater camera carried by the system obtains an underwater on-the-spot picture; the computer vision software extracts an image feature; a relative distance between an underwater structure and a preset position is obtained by using a built-in algorithm; and a difference of elevation or a tooth malocclusion parameter between two adjacent regular structures is measured by extracting other features of the picture. Therefore, a plane attitude or relative position of a structure can be reflected; and an objective of assisting in precise installation of underwater work can be achieved.