The invention relates to an underwater slope similar model experiment monitoring device, comprising a base composed of a plurality of rod members; the base is provided with a vertical support; the support is provided with monitoring rods used for arranging elements to be monitored. The underwater slope similar model experiment monitoring device is suitable for an underwater slope model experiment, employs a frame-type design, is simple to manufacture, and occupies a small space; the monitoring elements are installed on the support and the base after off-site arrangement, thereby saving time, simplifying an element installation process, and solving the difficulty of underwater installation.