Rapid decompression resulting from abrupt depth changes during the ascent of deep - sea aquaculture cages can induce severe stress or even mortality in physoclistous fish,becoming a critical bottleneck in the development of offshore aquaculture. In this study, Larimichthys crocea was used as a model species to investigate behavioral and physiological responses under different decompression rates and staged decompression strategies. A laboratory-based hyperbaric simulation system was constructed to replicate the ascent process from 20 m depth(200 kPa) to the surface. Two decompression modes constant rate and staged decompression were designed, with behavioral responses recorded and quantified using image processing techniques. Key metrics included instantaneous swimming speed,surface probing frequency,and tail beat frequency. Results showed that under constant-rate decompression,fish exhibited the most stable behavior at 10 kPa/min,with an average swimming speed of 0. 028 m/s, probing frequency of 18 times/min, and tail beat frequency of 1. 61 Hz. In the staged decompression group,a 5-minute pause at 50 kPa ( approx. 5 m depth) significantly alleviated stress,with swimming speed decreasing from 0. 085 to 0. 037 m/s,probing frequency from 31. 11 to 1 time/min,and tail beat frequency from 1. 56 to 0. 52 Hz. Over half of the individuals displayed clear behavioral recovery during the pause,a pattern not observed in other treatments.These findings indicate that a decompression strategy combining a moderate rate( 10 kPa/min) with a brief pressure hold at 50 kPa can effectively balance operational efficiency and animal welfare. This study provides a scientific basis for decompression management during cage lifting in the offshore farming of L. crocea and other physoclistous fish.