The extensive use of antibiotics in industrial and agricultural activities has resulted in environmental deterioration, drug residues, bacterial resistance, and imbalanced microbial structure in the marine environment, affecting the function of the marine ecosystem. To understand the seasonal distributions of microbial communities and resistance genes in the sea area of Changli County, Qinhuangdao City, metagenomic sequencing technology was used to sample and analyze the seawater, sediments, and intestinal contents of the local fish, Synechogobius hasta. The microbial composition of the seawater samples in Changli County was mainly bacterial. Proteobacteria was the most dominant bacterial phyla, with Photobacterium being the most abundant genus. The main types of antibiotic resistance genes in seawater were APH2_IIa, vanXYG, OXA_325, and TriC, whereas in sediments were bcrB, vanHO, adeS, and EreA. Meanwhile, the main types of antibiotic resistance genes in the intestinal contents of the Synechogobius hasta were msrE, emrK, and QnrB4. Network analysis revealed that microbial genus level in the sea area was highly associated with antibiotic resistance genes, and the main genera were multi-resistant strains. The efflux pump of antibiotics is the main antibiotic resistance mechanism in this microbial community. The scallop farming area in Changli County is rich in antibiotic resistant bacteria and genes, which align with the commonly used antibiotic categories in aquaculture production. Enhancing the continuous monitoring of antibiotic-resistant bacteria and genes in the aquaculture area is urgently required.