［Objective ］ This study aimed to investigate the effect of exogenous additives on gel properties of crawfish surimi products.［Methods ］ The experiment was designed with different amounts of hydroxypropyl distarch phosphate (HPDSP ),soy protein isolate (SPI),and glutamine transaminase (TGase ).After clarifying the addition amounts of the above three exogenous additives (HPDSP,SPI,TGase ),the effects of the three additives alone and the combination of the three additives (HST ) on the gel strength,water distribution,rheological properties,protein secondary structure,and microstructure of crayfish surimi were clarified,respectively.［Results］ The results showed that the best gel characteristics of crayfish surimi were obtained when HPDSP,SPI,and TGase were added at 2%,7%,and 0.6%,respectively (P<0.05).Compared with the control group,the addition of HPDSP,SPI,and TGase all improved the gel strength,textural properties,and water -holding capacity of crayfish surimi (P<0.05).Meanwhile,all three additives could help to enhance the energy storage modulus (G') of the surimi gels,and the G' value of the HST group was significantly higher than that of the rest of the groups (P<0.05).The protein secondary structure of the surimi gel was the best (P<0.05),and the protein secondary structure of the surimi gel was the best (P<0.05).The secondary structure of proteins showed that the three additives decreased the relative content of random curls and α-helices,and increased the relative content of β-folds and β-turns of proteins in the surimi.The scanning electron microscopy showed that the HST group had a dense and organized gel network structure.［Conclusion ］ Compared with adding a single additive,the combination of HPDSP,SPI and TGase can better improve the gel characteristics and water retention ability of crawfish surimi products.The combined use of the three exogenous additives has a synergistic effect on improving the gel of crawfish surimi products.