The invention relates to the field of residual oil utilization and discloses a method for high-yield low carbon olefin and a system for high-yield low carbon olefin. The method comprises the followingsteps: introducing a residual oil raw material into a fluidized bed hydrocracking reaction zone, performing a hydrocracking reaction, separating a hydrocracking reaction effluent, introducing a wax oil fraction into a first reactor and a second reactor in sequence, carrying out a catalytic cracking reaction, and introducing first light naphtha into a third reactor in a catalytic cracking reactionzone, and performing another catalytic cracking reaction; separating catalytic cracking products obtained from the second reactor and the third reactor in the catalytic cracking reaction zone, respectively circulating circulation oil and second light naphtha into the first reactor and the third reactor in the catalytic cracking reaction zone, and circulating catalytic cracking oil pulp into the fluidized bed hydrocracking reaction zone. With the organic combination of a fluidized bed residual oil hydrogenation process with a catalytic cracking process, the yield of high-value products such aspropylene and ethylene in the combined processes can be remarkably increased.