In order to obtain a better low-temperature storage performance, with tilapia filletsas the test material, an experimental research on the non-phosphorus water-retention agent and its formula based on the physical properties of tilapia fillets was carried out. On the basis of the detection of the conventional index for water retention, the best scope of water retention concentration for tilapia fillets was determined by LF-NMR based on the influences of sodium citrate, xylose, chitosan and other single factors on the freezing storage quality of tilapia fillets, and L9(34) orthogonal experiment for compounding and optimizing was carried out. The results showed that comparing with the tilapia fillets treated by compound phosphate water-retention agent, the tilapia fillets treated by compound non-phosphorous water-retention agent composed with 0.5% sodium citrate, 0.2% of xylose and 3.0% chitosan are higher on soaking weight gain rate, cooking loss rate and texture characteristics by 13.56% to 44.09%. In addition, for the sample treated by compound non-phosphorous water-retention agent, the loss rate after being thawed is not obvious; the water retention properties is overall good; and can offset the food safety problems caused by the adverse reactions to composite phosphate. This study provides new ideas for the development of non-phosphorous water-retention agents,which is expected to be widely used in practical production.