A method to promote the activity of a catalyst for dehydrogenation of propane to propylene is as follows: (1) an inorganic oxide bonding agent, a promoter and an acid solvent are added into a heat-resistant oxide; then after the oxide bonding agent, the promoter, the acid solvent and the oxide are kneaded evenly, the oxide is molded by rolling or band-extruding; (2) the catalyst carrier prepared is dried for 2 to 10 hours under the temperature of 60 centigrade degrees, and calcined under the temperature of 400 to 800 degrees; (3) the calcined carrier is immersed in a rare earth metal water solution under the temperature of 60 to 100 centigrade degrees for 2 to 10 hours; (4) the catalyst carrier modified by the rare earth is immersed in a water solution comprising platinum metal elementsand the fourteenth metal elements under the temperature of 400 to 600 centigrade degrees for 2 to 10 hours, and then the carrier is filtered, washed with distilled water, dried under the temperature of 60 to 180 centigrade degrees for 2 to 10 hours, and calcined under the temperature of 400 to 600 centigrade degrees for 2 to 10 hours; (5) the catalyst prepared is activated in the air under the temperature of 400 to 600 centigrade degrees for 3 to 10 hours, and reduced in a hydrogen flow under the temperature of 400 to 600 centigrade degrees for 2 to 10 hours; the reduced catalyst is used for catalytic reaction for dehydrogenation of propane to propylene.