Sulfonic gemini surfactant 1,6 -bis (N-dodecyl-N-propane sulfonate sodium)-hexane (12-6-12(SO3)2) was prepared with dodecylamine, 1,6-dibromohexane and 1,3-dibromopropane as starting materials by the polar head group joining method and the spacer joining method．The structure of the intermediates and final product was characterized, and the surface activity of the final product was measured．The structures of intermediates and target products were confirmed with 1H NMR and ESI-MS. The performance results showed that the critical micellar concentration (CMC) of 12-6-12(SO3)2 at 30oC is 0.015 mmol/L and its surface tension is 33.50 mN/m. The CMC of 12-6-12(SO3)2 is only 0.002 times of the similar sulfonic salt surfactant of SDS （25oC, 8.0 mmol/L）, and it is of about 0.31 times of the similar sulfonic gemini surfactant 1,3 -bis (N-dodecyl-N-propane sulfonate sodium)-propane (12-3-12(SO3)2)（25oC, 0.048 mmol/L）．