The invention discloses a catalytic cracking method for reducing carbon dioxide emission, in order to solve the problems of trapping and economic utilization of CO2 in the catalytic cracking process. The method comprises steps of: injecting a preheated hydrocarbon feedstock into a reactor riser; contacting and reacting the feedstock with a regenerated catalyst to generate an oil gas product and a spent catalyst; stripping the spent catalyst, sending the spent catalyst into a regeneration riser, contacting the spent catalyst with sectionally entered pure oxygen for a charring regeneration reaction to generate flue gas with high CO2 concentration and the regenerated catalyst; and sending the regenerated catalyst into a reactor for recycling. The method can realize a CO2 concentration higher than 95v% in dehydrated flue gas, thus realizing trapping and economic utilization.