An ammonium Gemini surfactant (C18-6-C18•2Br-) was synthesized from N,N-Dimethyloctadecylamine and 1,6-dibromohexane. The surfactants were characterized via IR spectra, 1H NMR spectra and elemental analysis，and the results prove that they are all the objective products．The critical micelle concentration of C18-6-C18•2Br- and Octadearyl dimethyl ammonium chloride (1831) were characterized by surface tension. The results indicate that C18-6-C18•2Br- has good surface active,and its critical micelle concentration is 2.13×10-5mol•L-1, The critical micelle concentration of C18-6-C18•2Br- was lower than the critical micelle concentration of a magnitude of octadearyl dimethyl ammonium chloride (1831).Study on clean fracturing fluid using C18-6-C18•2Br-, sodium salicylate and potassium chloride was done inlaboratory. The experimental results show that Gemini surfactants can be formed stable micelles at low concentrations.in high temperature, and it has good resistance to shear capacity, at 110 ℃ in 170 s-1 shear rate, shear continuous 60 min, viscosity remains at 60 mPa•s at least; has good performance of gelout, Fracturing fluids encountered kerosene and salt water can quickly break the glue, and the residue is almost zero, with a small formation damage; Core damage experiment shows that formation damage is small of this fracturing fluid system. The fracturing fluid hsa good heat resistance and viscoelastic.