Background and objectives: Paocai (pickled cabbage), which is fermented by lactic acid bacteria, is a traditional Chinese food. The microorganisms of Paocai were isolated and identified, and the constipation inhibition effect of one of the isolated Lactobacillus was investigated. Materials and Methods: The 16S rDNA technology was used for microbial identification. A mouse constipation model was established using activated carbon. After intragastric administration of Lactobacillus (109 CFU/mL), the mice were dissected to prepare pathological sections of the small intestine. Serum indicators were detected using kits, and the expression of small intestine-related mRNAs was detected by qPCR assay. Results: One strain of Lactobacillus was identified and named Lactobacillus fermentum CQPC03 (LF-CQPC03). Body weight and activated carbon propulsion rate were all higher in mice intragastrically administered with LF-CQPC03 compared with the control group, while the time to the first black stool in treated mice was lower than that in the control group. Serum assays showed that gastrin (Gas), endothelin (ET), and acetylcholinesterase (AchE) levels were significantly higher in the LF-CQPC03-treated mice than in the control group, while somatostatin (SS) levels were significantly lower than in the control mice. Mouse small intestine tissue showed that c-Kit, stem cell factor (SCF), and glial cell-derived neurotrophic factor (GDNF) mRNA expression levels were significantly higher in the LF-CQPC03 treated mice than in control mice, while transient receptor potential cation channel subfamily V member 1 (TRPV1) and inducible nitric oxide synthase (iNOS) expression levels were significantly lower in the LF-CQPC03 treated mice than in control mice. Conclusions: There is a better effect with high-dose LF-CQPC03, compared to the lower dose (LF-CQPC03-L), showing good probiotic potential, as well as development and application value.