The invention discloses a process for preparing an oyster sauce, which includes the following steps: cleaning fresh oyster meat and removing skin, leaching, vacuum blanching or boiling for one hour by using a jacketed pan, then pulping formula amount of the oyster meat, the oyster granularity in the stuff being 2-3mm, adding formula amount of auxiliary material, finally adding seasoning mixed powder, and mixing uniformly, stirring and heating the mixed material in the jacketed pan to 85-90 DEG C, then canning, exhausting for 10min at 90 DEG C, sterilizing for 15min at 115 DEG C, and then preparing a finished product. The oyster sauce rationally uses various nutrients rich in the oyster, and the meat is fresh, tender, delicious and nourishing, so the oyster sauce is a food with high quality and nutritive value.