The application belongs to the technical field of bioactive extract preparation, and discloses a preparation method of high-purity animal
placenta extract with controlled enzymolysis and molecular weight, which comprises sequentially connected
raw material low-temperature homogenization treatment, gradient temperature-controlled enzymolysis, transient mild
enzyme inactivation, double-mode membrane
fractionation for molecular
weight control, low-temperature concentration, activity locking and
sterile filtration. The application adopts a complex
protease system matched with a segmented gradient temperature-controlled enzymolysis process, and combines a neutral mild pH environment of 6.3-7.8 to accurately control the enzymolysis site and degradation degree, completely solve the technical problems of uncontrollable enzymolysis, excessive degradation or insufficient degradation and excessive large molecule residue caused by single enzymolysis and extensive enzymolysis in the traditional process, and greatly improve the uniformity of the enzymolysis process, thereby guaranteeing the stable quality of the extract from the source and being beneficial to actual application and operation.