Abstract: The extraction conditions of tannin Carya cathayensis sarg peels were optimized by response surface analysis (RSA) .Extraction time, extraction temperature, liquid to material ratio and mesh size were selected as factors based on single-factor test and the optimal extraction conditions had been developed by the method of Central Composite Design.On the basis of this, integrated technology of membrane to purify leach liquor of Carya cathayensis sarg peels were employed with these methods of microfiltration, ultrafiltration and reverseosmosis, and then spray drying.The research showed that the optimized extraction technology of tannin in Carya cathayensis sarg peels were:extraction time 95min, temperature 65℃, liquid ratio 1∶16 and mesh size 50.Under these conditions, the tannin yield ratio was 21.32mg/g and the purity was 80.3%.