The work aims to identify the most appropriate proportion of complex preservatives combined with tea polyphenols, mustard and vinegar by response surface methodology in order to prolong the shelf life of uncooked tuna sashimi effectively under partial freezing. The well prepared complex preservative was used for verification and the sense, texture, color difference, content of met-myoglobin, APC(aerobic plate count), TVB-N and K value of tuna sashimi on the 0th, 2nd, 4th, 6th, 8th, 10th and 12th day were measured. The results showed that the best ratio of complex preservatives was tea polyphenols 0.38%, mustard solution 8% and vinegar 15.69%, the shelf life of raw tuna has been extended for 4 d. The improved complex preservatives can effectively prolong the shelf life of uncooked tuna sashimi under the cold storage of −2 ℃.