This paper investigated the secondary cracking of gasoline and diesel from the catalytic pyrolysis of Daqing atmospheric residue on catalyst CEP-1 in a fluidized bed reactor. The results show that the secondary cracking reactivity of gasoline and diesel is poor, and the yield of total light olefins is only about 10% (by mass). As reaction temperature increases, ethylene yield increases, butylene yield decreases, and propylene yield shows a maximum. The optimal reaction temperature is about 670 degrees C for the production of light olefins. With the enhancement of catalyst-to-oil mass ratio and steam-to-oil mass ratio, the yields of light olefins increase to some extent. About 6.30% of the mass of total aromatic rings is converted by secondary cracking, indicating that aromatic hydrocarbons are not easy to undergo ring-opening reactions under the present experimental conditions.