The energy flow in food web is of great significance for maintaining the structure, function, and stability of marine ecosystem, and helps to gain a deeper understanding of the trophic dynamics and importance of the food web in marine ecosystems. This study constructed a linear inverse model with markov chain monte marlo (LIM-MCMC) based on seasonal biological resource survey data conducted in the Lvsi fishing ground in 2023, and combined it with ecological network analysis (ENA) to explore the energy flow characteristics and ecosystem status of the food web in the area. The results indicated that marine organisms in this area could be divided into 22 functional groups, forming a total of 224 energy flow pathways. The energy assimilated by planktonic animals was transmitted upwards through functional groups such as Konosirus punctatus, other benthic organisms, and other mollusks, to maintain the growth, development, and reproduction of high trophic level organisms. Although planktonic animals have 21 energy outflow pathways, the vast majority of their ingested energy was lost through resporation at 1764.70 kg/(km2 ·year), rather than transferring to high trophic levels. In addition, the total system throughput (TST), total primary production (TPP), total primary production/total respiration (TPP/TR), and connectance (C) were 5421.34 kg/(km2 ·year), 1803.92 kg/(km2 ·year), 1.00, and 0.41, respectively. Additionally, the five ecological network analysis (ENA) indicators, including extent of development (AC), constraint efficiency (CE), Finn's cycling index (FCI), synergism index (b/c), and dominant indirect effects (i/d), of the ecosystem in this study area were 0.93, 0.75, 0.24, 1.32, 5.46, respectively. Compared with other marine ecosystems, this marine ecosystem was larger in scale and more mature, with a relatively complex food web structure that could resist external disturbances to a greater extent. In addition, the development space of the ecosystem in this sea area was relatively large, with low network constraints, low energy utilization efficiency, and high sustainability. This study will contribute to the in-depth study of the nutritional dynamics of the food web in the Lvsi fishing ground and provide scientific basis for the scientific management of fishery resources in the area.