To investigate the effect of Antarctic krill oil (KO) on dopaminergic neurons and gut microbiome in Parkinson's disease (PD) mice， the method of intraperitoneal injection of 1-methyl-4-phenyl-1，2，3，6-tetrahydropyridine (MPTP) were used to construct PD subacute model in mice. The mice were divided into Control group， PD group， KO_PD group and KO group. The immunohistochemical technique of TH was used to evaluate the protective effect of Antarctic krill oil on dopaminergic neurons and nerve fibers in PD mice. Combined with HE staining of colon and 16S rDNA high-throughput sequencing of feces， the effect of KO on the intestinal structure and intestinal microecology of PD mice was studied. The results indicated that， compared with the PD group， the number of TH-positive cells in the substantia nigra of the brain was significantly increased by about 5-fold， the number of epithelial cuprocytes was increased by about 2-fold， and the phenomena such as thinning of colonic intestinal glands were improved in the KO_PD group of mice. The gut microbiota of PD group mice was disrupted， while KO intervention significantly increased the relative abundance of Bacteroidetes phylum， Dubosiella genus， and Muribaculaceae_unclassified genus， Streptococcus genus， etc.， and significantly downregulated the relative abundance of Firmicutes phylum， Alistipes genus， Clostridiales_ unclassified genus and Helicobacter genus， etc. To sum up， oral administration of KO can effectively improve the loss of dopaminergic neurons in the substantia nigra and structural changes in the colon tissue of mice induced by MPTP injection， and maintain the homeostasis of mice gut microbiota at various levels. This effect may be related to the regulation of glucose metabolism， amino acid metabolism， and lipid metabolism， etc.， in gut microbiota.