In the paper, the effect of the nanofiltration on lotion of porous resin has been studied in attempt to replace the traditional low-temperature and three-effect evaporation in the process of GBE (Ginkgo biloba extract) production. Based on the molecular weight of active component, G, K, L, three flat sheet membranes were adopted in the work. Taking into account all these factors, we choosed K, L to operate single factor experiment, and investigated the effect of operating pressure, recycling capacity, and raw material concentration on permeate flux, permeate concentration and content of effective component, and certified the optimum operating conditions. According to the experiments, we obtained the optimum operating condition: operating pressure: 1.2-1.5 MPa. recycling capacity: 100-140 1/h. Comparing the two membranes, L is bigger than K in permeate flux. permeate concentration and content of effective component. And the rejection rates are all about 99%. Then we choosed membrane L, operating condition: operating pressure: 1.2-1.5 MPa, cycling capacity: 100-140 1/h.