The invention discloses a method for establishing a primary cell culture system of a hippocampus. The method comprises the following steps: sterilizing the surface of a living hippocampus; taking outan embryo or a liver under an aseptic condition; rinsing the embryo or the liver with a rinsing culture solution, and then digesting the embryo or the liver with trypsin; removing impurities by filtering; carrying out centrifuging; removing supernatant; resuspending a cell precipitate with a primary growth culture solution to obtain a single cell suspension; transferring the single cell suspensioninto a culture flask added with the primary growth culture solution for culture; and replacing the primary growth culture solution in a half-volume liquid replacing mode every 2-3 days. According tothe method provided by the invention, a stable primary cell culture system of the hippocampus is established, and a foundation for research in the fields of hippocampal germplasm resource preservation, cell biology, immunology and the like is laid. The primary cell culture system of a hippocampus erectus is simple to operate, strong in repeatability and stable in cell growth, and can also be applied to the construction of primary culture systems of cells of other syngnathidae fishes.