The invention discloses a method for separating olefin and hydrogen from rupture gas. The method contains: putting the feed-in gas into the front depropanizing tower or the front deethanizing tower, sending the separated gas phase A into film separation process to be separated into hydrogen-rich stream C and hydrocarbons-rich stream B; then sending the hydrocarbons-rich stream B into cryogenic separation process. This method contains substantially the following steps: gas-liquid separation in front depropanizing tower or the front deethanizing tower, hydrogen-hydrocarbons film separation, and hydrocarbons-rich cryogenic separation. With the method, the recovery of hydrogen in the raw-material cracking gas comes up to more than 20%, purity of hydrogen comes up to more than 995v% and recovered hydrogen can be as hydrogenation raw gas material directly, and the energy consuming of cryogenic separation system reduces at least by 14.1% for part separation of hydrogen. The process flow is simple, the operation is simple, the energy consumption is low, and it especially suitable for ethylene industrializing device.