This study aimed to explore efficient methods for recycling slaughterhouse by-products by comparing the effects of single-enzyme and complex enzyme hydrolysis on the recovery of waste animal proteins， thereby providing a foundation for their high-value resource development. Employing single-factor experiments and response surface methodology (RSM)， This study investigated the impacts of enzyme dosage， hydrolysis time， and temperature on the quality and transfer efficiency of solid and liquid phase proteins using the meat and bone meal (MBM) as raw material. Product characteristics were analyzed through protein electrophoresis and free amino acid content. The results showed that the optimal volume ratio of alkaline protease to neutral protease was 7∶3. The optimized complex enzyme hydrolysis conditions were determined as pH 10， hydrolysis time 10.5 h， temperature 50 ℃， and enzyme dosage 13 000 U， achieving a protein transfer rate of 78.05%. The significance of factors affecting protein transfer rate followed the order: Enzyme dosage > hydrolysis time > temperature. Protein electrophoresis demonstrated that multi-enzyme hydrolysates had the smallest peptide molecular weight， with a negative correlation between product molecular weight and protein transfer efficiency. Free amino acid analysis indicated that the complex enzyme treatment group exhibited the highest content (4 088 mg/L). In conclusion， complex enzyme hydrolysis significantly enhanceed protein solubility and transfer efficiency. The optimized compound enzymatic hydrolysis process was feasible and provided theoretical and technical support for the further development of amino acid peptide water-soluble fertilizers.