The invention provides a catalyst used in preparation of low-carbon alcohol by a synthesis gas by using flake graphite or graphene as a carrier, a preparation method of the catalyst and application of the catalyst to preparation of the low-carbon alcohol. The catalyst is used for synthesizing the low-carbon alcohol by using the synthesis gas, and has the characteristics of high CO conversion rate, good selectivity of 2-carbon or more-carbon alcohol, good low-temperature activity, and the like. The preparation and treatment process is simple and suitable for industrialized production. According to the basic preparation principle, all metal ions, especially copper ions and cobalt ions in a catalyst precursor are uniformly mixed by controlling a coprecipitation condition; because metal and graphite have a strong interaction, Cu-Co nanometer alloy can be highly dispersed on a graphite flake after reduction, and thus particle sintering caused by migration of the CuCo alloy can be effectively prevented.