The invention discloses a production method for producing oyster hydrolyzed protein powder and oyster sauce at the same time. According to the invention, a traditional seasoning-oyster sauce, can be prepared through concentrating and collecting juice which is dripped when a shell is broken to take meat, as well as when the meat is minced and centrifugal; low-temperature acid base is adopted to remove a fatty oil which is easy to cause fishy smell, and a macroporous resin is adopted to absorb colored impurity, so that the fishy smell can be cleared; and a hydrolyzed protein powder can be obtained through the following steps: anion and cation resin desalination, concentration and spray dehydration. The method provided by the invention has the benefits that the hydrolyzed protein powder is pure white in color, is not fishy and tasteless, and is high in production, and can serve as nutritious foods, health care products and food additives; and the oyster sauce is a delicious sauce.