In this paper,the bioreactor with micro-filtration membrane was developed and prepared for the liquid starter used directly for pickle fermentation.The results showed that,the pH,temperature,dissolved oxygen and time for nutrients addition could be controlled by this bioreactor and the viable cell concentrations of Lactobacillus plantarum reached(5~8)×109 CFU/mL with constant pH after 12 h.Under the optimum operation conditions of membrane filtration(the peristaltic pump speed 50 r/min and the pressure 0.15 MPa),the viable cells of the concentrated broth was about(2~3)×1010 CFU/mL,and the suspensions could be used as the starter after diluted by 5000-fold.Under room temperature,the high-quality pickle was obtained after 3 d,less than the natural fermentation of 2 d.With its simple structure,convenient use and high degree of automation,this bioreactor is suitable for continuous large scale industrial production of pickle fermentation.