The invention discloses a catalytic cracking method for producing propylene, comprising the following steps: contacting heavy feed stock with a first stream of a catalyst containing shape-selective zeolite with an average pore size being less than 0.7nm in a first riser reactor to conduct cracking reaction, then separating the oiling agent, introducing oil gas into a product separation system, and introducing the catalyst into a stripper or a fluidized bed reactor; contacting the recycled cracking heavy oil with a second stream of the catalyst containing shape-selective zeolite with an average pore size being less than 0.7nm in a second riser reactor to conduct cracking reaction, then letting the obtained oiling agent mixture and the light hydrocarbon introduced into the second riser reactor be subject to contact reaction, then introducing the reaction mixture into a fluidized bed combined reactor for reacting, introducing the reacted oil gas into the product separation system, and introducing the reacted catalyst into the stripper. According to the invention, the method is used for heavy oil catalytic cracking, the heavy oil conversion rate is high, the yields of propylene and butene are high, and the selectivity of dry gas and coke is good.