In this experiment， through multiple catalytic transesterification methods， the relationship between lipase activity and structure under optimal catalytic conditions and the activity regeneration technology of low-activity lipase are studied. Fluorescence spectroscopy and Fourier transform infrared spectroscopy were used to analyze the tertiary and secondary structures of lipases and the relationship between changes in lipase activity and its secondary tertiary structure. Low-activity lipases were restored by treating lipase with isopropanol and mixed fats. The study results showed that with the decrease of lipase activity， the fluorescence intensity of lipase increased gradually， and the amino acid leakage was more and more. In the secondary structure， the α-helix content decreased and the β-sheet content increased gradually. Through isopropanol treatment， the lipase activity was restored to 75.00% of the original lipase； through the mixed oil treatment， the lipase activity was restored to 96.60% of the original lipase， realizing the purpose of high-efficiency catalytic restoration.