The invention provides a pearl nucleus with the surface covered with a high-molecular tissue engineering scaffold material and a preparing method thereof. The pearl nucleus covered with a high-molecular tissue engineering scaffold material comprises a pearl nucleus body and is characterized in that the surface of the pearl nucleus body is covered with a tissue engineering scaffold made of the biodegradable high-molecular material. An extracellular matrix environment which is suitable for the attachment, migration and mitosis and growth of cells and having a basically uniform thickness is formed on the outer surface of the pearl nucleus body; after inoculation of mantle cells, the mantle cells can form a pearl sac with a basically uniform thickness around the pearl nucleus. The method solves the problem of traditional mantle cell piece implantation method that cells are not distributed uniformly after migration around pearl nucleuses and thus cause strangely-shaped pearls, greatly increases the proportion of round excellent pearls, guarantees great compatibility of pearl nucleuses and pearl mussels, prevents nucleus spitting and thus increases the economic benefits of pearl culture.