A process for increasing the yield of ethylene and propylene, comprising: (1) feeding a feedstock into a reaction zone with a catalyst to produce (i) a product stream and a catalyst to be regenerated; (2) stripping and then dividing the catalyst to be regenerated into at least two parts, wherein a first part is recycled into the reaction zone at a first position, and a second part is regenerated in the regenerator to form a regenerated catalyst and then recycled into the reaction zone at a second position; and (3) controlling the temperature increase in the reaction zone.