The paper aims to develop a safe and effective natural preservative for the use of soft-packaged, pre-conditioned, pickled pepper pork livers. The effects of garlic extract, acetic acid and lactic acid on the inhibition of the dominant spoilage bacteria in the pork livers of pickled pepper were investigated separately. After screening the superior concentration range of the three, the response surface method based on fuzzy mathematical evaluation was utilized to op-timize the formulation of compound preservatives. The optimized formulation of compound preservatives was used to conduct constant temperature storage experiment of pickled pepper pork livers at 25 ℃. The best formulation of natural compounded antibacterial agent was: Using 1000 g of pretreated pork liver slices as a benchmark, the following bacteriostatic agents were prepared by mass ratio: acetic acid 2.3%, lactic acid 4.5%, garlic extract 0.365%. The combined score of actual antibacterial effect on pickled pepper pork liver was 1.074 points, which was close to the predicted value of 0.93 points. Under the condition of 25 ℃, the antimicrobial preservative can significantly inhibit the growth of microorganisms and maintain the quality of pork liver. The group extended its shelf life up to 21 d, which was 50% longer than that of the blank treatment group, showing delightful freshness preservation effect. Based on the ingredients of the product itself, this study uses its antiseptic and antibacterial properties to achieve the purpose of freshness preservation, and provides a new way of thinking about the future development of antibacterial and freshness preservation agents for pre-prepared dishes.