Abstract: Identifying the spatiotemporal distribution of coastal fish resources and their environmental associations is essential under the combined effects of climate change and intensified human activities. Based on bottom trawl survey data collected in autumn from 2021 to 2023 and multi-source satellite-derived environmental data, this study used generalized additive models (GAMs) and random forest (RF) models to analyze the spatiotemporal distribution patterns of Collichthys lucidus in the coastal waters of Jiangsu, China, and its relationships with major marine environmental factors, and to reconstruct its suitable habitat distribution during autumn from 2018 to 2023. The results showed that both resource biomass and resource abundance exhibited pronounced interannual variability, characterized by high values in 2021, a marked decline in 2022, and recovery in 2023. High-value areas were consistently concentrated in the Yangtze River estuary and the shallow nearshore waters of central and southern Jiangsu. Model comparison indicated that the resource abundance index provided a more stable representation of environmental responses. After considering predictive performance, response-variable suitability, and the need for ecological interpretation, GAM was selected as the working model for autumn habitat reconstruction. Water depth, sea surface temperature, sea surface salinity, meridional current velocity, zonal current velocity, and eddy kinetic energy were identified as the major environmental factors influencing the autumn distribution of C. lucidus. Habitat reconstruction suggested that its distribution remained concentrated in nearshore waters. These findings provide scientific support for coastal fishery resource assessment and spatially explicit management.