The invention discloses a high-performance catalyst used for preparing low alcohol by synthesis gas and a preparation method thereof. The structural formula of the catalyst is M1a-Mob-M2c-CNTsd-S, wherein M1 stands for one or two of Co or Ni, M2 stands for one or several of alkali metals such as K, Na and Cs, S stands for a complex oxide support TiO2-SiO2 orSiO2-Al2O3, a, b, c and d stand for the mass fractions of each substance in the catalyst respectively, a=10%-20%, b=20%-40%, c=0%-5%, d=10%-20%, and the balance is the complex oxide support. According to the catalyst, the preparation method is simple, an in-situ supporting mode is mainly adopted, the metals and carbon nano tubes are deposited onto the support, then spray-drying is conducted to obtain catalyst powder for the low alcohol with high-dispersion metals and evenly-distributed carbon nano tubes, and after roasting, the catalyst has the advantages of high C2+ alcohol yield and selectivity, high anti-sulfur ability and long lifetime.