Abstract: To explore the effects of pre-frying treatment on the gel and flavor characteristics of surimi products, mixed surimi (Nemipterus virgatus and Hypophthalmichthys molitrix) was used as the research object. The gel characteristics of fried surimi products (fish balls) under pre-frying treatment and direct frying conditions at 120, 140, 160, and 180 ℃, as well as the flavor characteristics of the mixed surimi system, were studied. The results showed that, compared with direct frying, pre-frying treatment presented positive effects, and the quality of fish balls was improved. With the increase of pre-frying temperature, especially when it reached 160 ℃, the gel strength of fish balls reached the highest value of 832.01 g·cm. The breaking force and breaking distance reached the maximum values of 653.79 g and 1.26 cm respectively. The hardness, springiness, cohesiveness and chewiness of fish balls were also the largest, being 1560.47 g, 1.01, 0.88 g, and 1247.86 g respectively. The water-holding capacity and low-field nuclear magnetic resonance results indicated that pre-frying treatment of fish balls could optimize the water distribution. The water-holding capacity of fish balls pre-fried at 160 ℃ reached 89.14%, and the increase in the peak area of T₂₂ proved that the water-holding capacity of fish balls under pre-frying treatment was better. In addition, Raman spectroscopy showed that pre-frying treatment with increasing temperature could improve the distribution of protein secondary structure inside fish balls. When the temperature was 160 ℃, the relative contents of β-sheet and β-turn reached 45.75% and 20.21% respectively. Microstructure observation showed that fish balls with pre-frying treatment presented a more compact and uniform network structure. Sensory flavor analysis showed that 53 volatile flavor substances with relatively high contents were detected in the 160 ℃ group with pre-frying treatment. The main components affecting the overall flavor of fried fish balls were 11 aldehydes, 6 alkanes, and 8 esters, accounting for 49% of the total flavor substances. The fishy smell of fish balls was significantly reduced, which was also confirmed by the sensory evaluation of flavor and taste. The experimental results indicate that pre-frying treatment can enhance the gel strength of surimi gel, increase the hardness of fish balls, promote the transformation of protein secondary structure and the cross-linking of protein structure, maintain the moisture in the gel system, and effectively improve the gel and water-holding characteristics of surimi gel. This study provides a reference for the processing and development of fried surimi products.