Abstract: In order to make a better use of different components in naphtha to produce ethylene and aromatics based on the strategy of molecular scale management, this article carried out the studies on the adsorption separation of normal paraffins from naphtha using 5A molecular sieves in a double-column fixed-bed. After 5 adsorption/desorption circles，the adsorption separation process reached dynamic balance. The optimal conditions for the adsorption/desorption process were an operation temperature of 270℃, a naphtha feed space velocity of 153.4h-1, a switch time of 30 minutes, using N2 as desorption gas and a space velocity of 127.5h-1, an intermediate oil cutting time of 2 minutes. The normal paraffin content in the raffinate oil was less than 3% and the potential aromatic content of the raffinate oil was 10% higher than that of the SGPC naphtha. The normal paraffin content of the desorption oil was over 95% and the ethylene yield was improved by 13%-14% using the desorption oil as stream cracking feed compared to the naphtha feed.