Objective  To investigate the neuroprotective effect and mechanism of cerebrotein hydrolysate-Ⅰ   (CHⅠon1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced Parkinson’s disease (PD) mice.     Methods Totally 36 healthy male C57BL/6 mice were randomly divided into control group(Ctrl), model group(MPTP) and CH-Ⅰ group. MPTP was used to induce PD model in mice, and CH-Ⅰ was injected intraperitoneally for intervention. The behavioral function of mice was detected by pole test, the expression of tyrosine hydroxylase (TH) was detected by immunohistochemistry, and the composition and diversity of intestinal microflora were detected by gene sequencing and bioinformatics analysis.    Results Compared with the control group, MPTP induced behavioral deficits in PD mice after modeling (P<0.05), after CH-Ⅰ treatment, the behavioral defects of PD mice were improved compared with MPTP group (P<0.05). Immunohistochemical result  showed that MPTP decreased the expression of the rate-limiting enzyme TH in dopamine synthesis, and increased the expression of TH after CH-Ⅰ treatment. The result  of microbial diversity showed that the intestinal microflora diversity of mice decreased after MPTP treatment (P<0.05). At the “phylum” level, the number of Epsilonbacteraeota and Deferribacteres decreased sharply, while the number of Verrucomicrobia increased significantly. At the level of “family”, the number of Desulfovibrionaceae, Lachnospiraceae, Helicobacteraceae and Rikenellaceae decreased, while the number of Akkermansiaceae and Erysipelotrichaceae increased, suggesting that the original homeostasis of intestinal microflora was destroyed. After CH-Ⅰ treatment, the number of intestinal microflora tended to be normal, which reduced the abundance of pathogenic microbiota and increased the relative abundance of beneficial bacteria.    Conclusion CH-Ⅰ can improve the composition of intestinal microflora and the behavioral function of PD mice by decreasing the abundance of pathogenic microbiota and increasing the relative abundance of beneficial bacteria.