Seedling breeding system for cold water fishes in plateau regions

The invention provides a seedling breeding system for cold water fishes in plateau regions. The seedling breeding system comprises a fish pond, a filter system, a sand filtration tank, an ultraviolet sterilization device, a fixed bed biological filter, a moving bed biological filter and an oxygen dissolving device, wherein an aeration device is arranged in the fish pond; a water outlet and a water outlet of the fish pond are communicated through an external pipeline; the filter system, the sand filtration tank, the ultraviolet sterilization device, the fixed bed biological filter, the moving bed biological filter and the oxygen dissolving device are sequentially arranged on a connection pipeline from the water outlet to the water inlet of the fish pond. According to the seedling breeding system, the sufficient dissolved oxygen concentration is realized, and the stable seedling breeding water temperature is maintained under natural conditions including low saturated dissolved oxygen concentration, large temperature difference between day and night and the like in the plateau regions.