In order to enhance the mechanical properties of gelatin gel and expand its application value, gelatin-citric acid-stearic acid composite gel was prepared by using gelatin as raw material, citric acid as cross-linking agent and stearic acid as additive. The preparation conditions of composite gel were optimized with compressive strength as the response value. The morphology of the composite was observed with a scanning electron microscope (SEM), the chemical structure was characterized by infrared spectroscopy (FT-IR), and the cytotoxicity and curcumin release were studied. The results showed that the optimized process conditions were as follows: the quality of stearic acid was 0.013 g/mL, the quality of citric acid was 0.015 g/mL, and the temperature was 69 ℃. The mechanical strength of the gelatin-stearic acid composite gel prepared under the optimal conditions was 117% higher than that of the single component gelatin gel (45.55 kPa). The FT-IR spectrum analysis showed that the secondary structure of gelatin was changed due to the cross-linking effect of citric acid, resulting in the formation of GA-CA-SA composite gel. The hydrophilic gelatin was arranged outside and the hydrophobic stearic acid was wrapped in it. Inside, a regular pore structure was formed. It has no cytotoxicity and has a good slow release effect on curcumin.