To develop composite probiotic fermented foods rich in γ-aminobutyric acid (GABA), this study systematically investigated the screening, biological characteristics, and probiotic potential of GABA-producing lactic acid bacteria from Badu sour bamboo shoots via methods including rapid indicator screening, 16S rDNA sequence analysis, phylogenetic analysis, and simulated gastrointestinal tract tests. Results showed that, a strain of Lactiplantibacillus plantarum SS5 with high GABA production capacity was successfully isolated. The strain exhibited a GABA synthesis activity of 0.27 mg/(h∙g _{wet cells}) through the conversion of L-glutamic acid. The strain SS5 was capable of growing within a temperature range of 20~40 ℃, with an optimal growth temperature of 30 ℃ and an optimal pH range of 6.0~7.5. Notably, the addition of 100 g/L NaCl to the MRS medium significantly inhibited its growth. Although strain SS5 exhibited certain tolerance to oxygen, microaerophilic conditions were found to be more conducive to its growth. Batch culture experiments showed that strain SS5 entered a rapid growth phase between 8~12 h post-inoculation and reached the stationary phase at 36 h. After treatment with acidic solutions, simulated gastric juice, bile salts, and simulated intestinal fluid, the survival rates of strain SS5 cells under simulated fasting conditions were determined to be 44.27%±1.19%, 70.61%±0.30%, 99.44%±0.66%, and 93.29%±0.83% respectively, and the corresponding relative specific growth rates were calculated as 127.72%±12.32%, 206.01%±5.24%, 97.28%±8.45%, and 98.61%±7.17% respectively. When using skimmed milk to simulate feeding conditions, the survival rates were determined to be 73.61%±0.52%, 74.53%±1.09%, 94.99%±0.64%, and 96.70%±0.44% respectively, and the corresponding relative specific growth rates were calculated as 150.62%±9.68%, 98.01%±2.30%, 95.77%±5.63%, and 89.61%±2.48% respectively. The results indicated that L. plantarum SS5 possessed robust GABA synthesis capabilities, excellent tolerance to gastrointestinal transit, and remarkable growth recovery potential, thereby demonstrating promising prospects for its application in the development of GABA-enriched composite probiotic fermented foods.