The invention discloses a preparation method and application of a silicon carbide-supported copper-based bimetallic catalyst. The preparation method comprises soaking a SiC carrier, copper nitrate and nitrates of other metals without copper in the same volume of deionized water, then carrying out calcining for 2h to obtain the silicon carbide-supported copper-based bimetallic catalyst having an expression formula of MxCuy/SiC. The silicon carbide-supported copper-based bimetallic catalyst has a copper loading ratio of 1-15% and has an other metal loading ratio of 1-5%. The catalyst can selectively oxidize alcohol into desired aldehyde or ketone in alcohol gaseous catalytic oxidation and has a conversion rate and selectivity of 99% or more. The catalyst is prepared through simple processes, has high stability and activity and has a lasting and stable reaction process.