As offshore aquaculture space resources gradually tend toward saturation, expanding into far-offshore aquaculture has become a strategic choice for expanding new space and achieving high-quality development of marine aquaculture; although the far-offshore has significant advantages in water environment quality and water exchange, it simultaneously exposes farmed fish to complex and variable water currents. Therefore, flow velocity has become a key factor influencing the growth, physiology, and behavior of fish in far-offshore aquaculture. Exploring the adaptability of fish to different flow velocities is crucial for developing healthy far-offshore aquaculture technologies and breeding current-resistant strains. Seriola aureovittata, as an oceanic and highly active fish species of high economic value, is widely regarded as an excellent species for far-offshore aquaculture due to its rapid growth and superior meat quality. This study focused on juvenile yellowtail kingfish with an average body length of (11.92 ± 0.43 cm), utilizing a controllable flow velocity swimming capacity test tank to comprehensively apply the incremental velocity method and constant velocity method to detect their critical swimming speed (Ucrit) and swimming duration (T), and combined high-speed video recording with the behavioral analysis software LoliTrack 5 to quantitatively analyze the inter-individual distance (IID), swimming velocity synchrony (Sv), tail beat frequency (TBF), and collective spatial arrangement patterns of schools in different sizes (n = 2, 4, 6, 8, 10) under ten flow velocity conditions (0.5 – 5.0 BL/s). The study systematically explored the effects of flow velocity on individual swimming capacity and collective swimming behavioral strategies, revealing adaptation characteristics to the far-offshore from the perspective of swimming behavior, providing a scientific basis for sea-entry acclimation, aquaculture management, and the optimization of fish-suitability in far-offshore aquaculture systems. Experimental results showed that juvenile yellowtail kingfish exhibited extremely strong current resistance; their absolute Ucrit was (1.10 ± 0.14 m/s) and relative Ucrit reached (9.25 ± 0.34 BL/s), values which are significantly higher than those of similar-sized Lateolabrax maculatus (0.86 m/s), Larimichthys crocea (0.40 m/s), and Sebastes schlegelii (0.39 m/s), reflecting their superior swimming capacity. In endurance tests, the swimming durations of juvenile yellowtail kingfish at flow velocities of 9.0 BL/s and 9.5 BL/s (1.07 and 1.13 m/s) were (216.17 ± 50.23 min) and (83.29 ± 21.31 min), respectively, and they could swim continuously for over 5 hours at flow velocities below 8.5 BL/s (1.0 m/s), highlighting the species"" robust aerobic metabolic reserve. Flow velocity, as a compulsive physical stimulus, significantly altered the swimming movement strategies of juvenile yellowtail kingfish schools; as the flow velocity increased from 0.5 to 5.0 BL/s, the (Sv) of schools with n ≤ 6 first decreased and then increased, and the smaller the school size, the larger the range of change; when the velocity was 2.5 BL/s, the (Sv) of the three groups reached bottom values of (0.32 ± 0.05), (0.42 ± 0.04), and (0.64 ± 0.02), respectively, while larger-scale schools (n = 8, 10) exhibited higher (Sv) under most flow velocities, reaching maximum values of (0.86 ± 0.03) and (0.83 ± 0.02) at 5.0 BL/s and 2.5 BL/s, respectively. With the increase in flow velocity, the inter-individual distance (IID) of schools of different sizes showed an overall downward trend, indicating that high-velocity environments prompt fish schools to form tighter collective arrangement structures to jointly resist hydrodynamic drag. Compared to small-scale schools, large-scale schools exhibited smaller inter-individual distances and higher synchrony under most flow velocity conditions, indicating that individuals in larger-scale schools can more easily maintain stable formations and collectively cope with the fluid environment. Regarding energy allocation mechanisms, with the increase in flow velocity, the TBF of juvenile yellowtail kingfish in schools of different sizes gradually increased and showed a linear positive correlation with flow velocity (r2 > 0.95). However, under the same flow velocity conditions, the larger the school size, the lower the individual tail beat frequency, indicating that collective swimming can effectively reduce individual energy consumption, revealing a clear "collective energy-saving effect." The arrangement patterns presented by juvenile yellowtail kingfish of different school sizes under various flow velocities were predominantly diamond-shaped; this formation is considered to have high hydrodynamic efficiency, and the proportion of square-shaped arrangement patterns gradually decreased as the school size increased. The study specifically identified 1.5 to 2.0 BL/s as the critical threshold interval for behavioral transition in yellowtail kingfish, during which the schools were in a formation-changing period of switching from "spontaneous exploratory swimming" to "forced rheotactic swimming"; group synchrony showed a phased decline and the proportion of square arrangements rose briefly, but as flow velocity increased, the schools would return to the hydrodynamically superior diamond arrangement to achieve an optimal energy strategy. In summary, juvenile yellowtail kingfish possess extremely strong swimming capacity; their collective movement synchrony and cohesion are interactively influenced by school size and flow velocity, with dense schools exhibiting greater stability. Furthermore, to reduce individual energy consumption, juvenile yellowtail kingfish schools primarily adopt the diamond-shaped arrangement pattern to cope with turbulent water currents; the study indicates that juvenile yellowtail kingfish have strong adaptability to far-offshore aquaculture environments, and the results provide a reference basis for the selection of current-resistant strains and the development of healthy far-offshore aquaculture technologies.