Objective To explore the optimal process of fermented bamboo shoots (Suansun) with sweet rice wine residue (Laozao) and analyze and compare their nutritional and volatile components.Methods Process parameters for co-fermentation of bamboo shoots with sweet rice wine residue are optimized using single-factor analysis, Plackett-Burman design, and Box-Behnken response surface methodology. The nutritional and flavor characteristics of the optimized product are compared with those of naturally fermented bamboo shoots.Results The optimized fermentation conditions are as follows: lactic acid bacteria inoculum of 0.20%, salt content of 5.00%, calcium chloride addition of 0.07%, and sweet rice wine residue dosage of 16.00%. Under these conditions, the comprehensive quality score of the co-fermented bamboo shoots reaches 90. Compared with natural fermentation, the optimized product exhibits a lower pH (2.73 vs. 3.89), higher total acidity (52.15 vs. 43.65 g/kg), and significantly elevated levels of total soluble sugar (0.15% vs. 0.04%), protein content (3.91% vs. 2.12%), and amino nitrogen (0.38% vs. 0.12%). Additionally, a greater diversity of volatile compounds is detected (21 vs. 10), with a notably higher total ester content (1.38% vs. 0.08%), and p-cresol was identified as the dominant volatile component (97.81% vs. 95.19%).Conclusion Compared with natural fermentation, co-fermentation with sweet rice wine residue imparts a mellower aroma and superior nutritional profile to the fermented bamboo shoots.