The invention discloses a two-stage PSA method for recovering C2+ from refinery dry gas according to concentration, which relates to the technical field of separating and recovery of in valuable substances in petrochemical tail gas. The method comprises a pretreatment process, a C2+ adsorption concentration process, an intermediate purifying process, and a C2+ adsorption refining process, wherein, the pre-treated refinery mixed dry gas is introduced into the CO2+ adsorption concentration process, then flowed non-adsorption phase gas is the adsorption exhaust gas, or directly taken as hydrogen (H2) product gas, or taken as fuel gas, or taken as raw material gas for extraction of hydrogen for output; the flowed adsorption phase gas forms the intermediate gas through the intermediate purifying process, and then is introduced into the C2+ adsorption refining process for refining, the flowed non-adsorption phase gas is taken as the raw material gas for mixing with the refinery mixed dry gas, a mixture is returned to the C2+ adsorption concentration process; the flowed adsorption phase gas has the C2+ concentration being more than 90-95% (a volume ratio), wherein the methane impurity concentration is less than 4%, the flowed adsorption phase gas is taken as the C2+ concentrate product gas for output, and the yield of C2+ is more than 90-95%.