The invention relates to a catalyst for synthesizing methanol by hydrogenating carbon dioxide and a preparation method thereof, belonging to the technical field of catalysts. The catalyst for synthesizing the methanol by hydrogenating the carbon dioxide comprises a mixed oxide of one or more of Cu, Zn, La, Ce and M, wherein M is Al, Si, Ti or Zr; the catalyst comprises the following components in percentage by weight: 30-70% of CuO, 10-40% of ZnO, 1-5% of accelerative activators Ln2O3, 1-5% of stabilizers CeO2 and 5-20% of carrier oxides MxOy. The preparation method of the catalyst comprises the following steps of: firstly mashing the carrier oxides MxOy; and then adding active matter components and precipitators into oxide slurry in a parallel flowing manner for coprecipitation. The catalyst disclosed by the invention has the advantages of high specific surface reaching 200 m<2> / g, stable structure, contact compactness among all the components and high synergistic effect, so that the catalyst has higher activity and selectivity; the preparation process of the catalyst has the advantages of simplicity, good repeatability and convenience for industrial production; in addition, by means of the catalyst disclosed by the invention, the conversion rate of the carbon dioxide is high and reaches 35 percent under appropriate reaction conditions, and the selectivity of the methanol is higher and reaches more than 80 percent.