The invention provides a method for producing propylene and coproducing ethylene from C4 olefins, which comprises the following steps: filling the mixture of an olefin disproportionation catalyst and a catalytic cracking catalyst in one reactor or sectionally filling the olefin disproportionation catalyst and catalytic cracking catalyst in differential reactors which are connected in series, and passing a C4 olefin raw material through the olefin disproportionation catalyst and catalytic cracking catalyst to carry out C4 olefin disproportionation reaction and low-carbon olefin cracking reaction, thereby generating the propylene and ethylene. The method couples a low-carbon olefin disproportionation technique with a low-carbon olefin deep catalytic cracking technique, and adopts an appropriate combination mode for the olefin disproportionation catalyst and olefin cracking catalyst, thereby achieving the goal of enhancing the yields of the propylene and ethylene.