The sodium alginate (SA) cation layer and the chitosan (CS) anion layer were modified by copper phthalocyanine tetrasulfonic acid (CuTsPc) and copper tetraaminophthalocyanine (CuTAPc) to prepare the CuTsPc-SA/CuTAPc-CS bipolar membrane(BPM)，which was used as a separator in an electrolysis cell for paired electro-generation of L-cysteine and L-cysteic acid. Experimental results showed that CuTsPc and CuTAPc promoted water spiliting in the interlayer and greatly decreased the membrane impedance and IR drop of the modified BPM. The IR drop of CuTsPc-SA/CuTAPc-CS BPM was only 0.3V in 1 mol/L Na2SO4 solution at 45 mA/cm2. Based on an overall consideration of current efficiency and yield, the optimum current density during the process of electrolysis was 35 mA/cm2.