Put 1kg fresh oysters directly or in water into the autoclave (capacity: 6L, pressure: 98kPa), add purified water (1L), boil for about 30 minutes under the pressure of 98kPa, restore normal pressure, filter and filter under reduced pressure to obtain milky white color liquid. Then, add 1L of pure water to the residue, boil for about 30 minutes, and after filtration, mix the filtrate with the original extract, and then distill the extract with vacuum (0.133-0.66kPa, temperature 70-80°C) to obtain Moisture was 67.34% of viscous terracotta flowable liquid 440g. The liquid was lighter than before vacuum distillation. The concentrate was instantaneously dried by an ordinary spray drying method (instantaneous hot air temperature: 180° C., outlet temperature: 80° C., dropping rate: 30 mL per minute), and 125 g of uniform pale yellow fine powder was obtained.