Abstract: The reaction performance of DCC light naphtha was investigated in a fixed fluidized bed reactor. The operating conditions including reaction temperature, WHSV, water/oil and catalyst/oil ratio, were investigated to selectively obtain light olefin from DCC light naphtha and meanwhile control the formation of methane. The results show that the suitable operating conditions for DCC light naphtha catalytic cracking are 650 ℃, 6 h-1, water/oil of 0.3 and catalyst/oil of 10. The ethylene yield is10.92%, the propylene yield is 27.74%, the butylene yield is 12.97% and total light olefin yield (ethylene + propylene + butylenes) is 51.63% for the DCC light naphtha containing 69.02% olefin under the optimized conditions.