Cationic dye of rhodamine b（RB） was removed by the enhanced precipitation of calcium dodecyl benzene sulfonate（Ca（DBS）2） from aqueous solution and the（Ca（DBS）2） particles were flocculated by microbial flocculant GA1. During this process, the sodium dodecyl benzene sulfonate（SDBS） solubilized the RB molecular, and under the effect of excessive amount of Ca2+, the SDBS micelles and the RB containing calcium dodecyl benzene sulfonate particles（CDBS-RB particles） were precipitated and finally flocculated by microbial flocculant GA1. The response surface methodology（RSM） was applied to optimize the reaction conditions including Ca2+ dosage, SDBS dosage and MBFGA1 dosage to increase the RB removal rate. When the initial concentration of RB was 50 mg/L and pH was 10, the optimal flocculation condition was SDBS dosage（2.67 mmol/L），Ca2+ dosage (5.61 mmol/L) and MBFGA1 dosage（4.34 mL/L）. Under this optimal conditions, the RB and SDBS removal rate were 99.80% and 90.03%, and the effluent value of COD is 89.69mg/L，which was lower than the national emission standard and did not need subsequent processing. The environmental scanning electron microscope (ESEM) analysis was used to explore the RB removal process and the reaction mechanism between Ca2+ and SDBS. In addition, when Ca2+ dosage was enough compared with SDBS dosage, the SDBS micelles containing RB molecular (SDBS-RB micelles) could assemble and shift to the formation of CDBS-RB particles. Finally, the CDBS-RB particles were flocculated by MBFGA1；When SDBS dosage was relatively excessive, the SDBS micelles could form in the solution and CDBS-RB particles could redissolve gradually in order to provide Ca2+ for the SDBS micelles.