API 50 CHL identification system and 16 S rDNA sequence alignment method were used to identify the strain. The model of diabetes mellitus in mice was established by high fat diet combined with streptozotocin. The auxiliary hypoglycemic effect of strain CH126 was evaluated by measuring fasting blood glucose, blood lipid, antioxidant index and insulin. The results showed that: the strain CH126 was identified as Lactobacillus plantarum by combining API 50 CHL and 16 S rDNA sequence analysis. Compared with model group, L. plantarum CH126 could significantly reduce fasting blood glucose and blood lipid levels, inhibit oxidative stress injury, improve intestinal barrier function, and increase insulin level. The above data indicate that L. plantarum CH126 is a probiotic with the function of reducing blood sugar.