The invention discloses a preparation method of a 
rare earth yttrium air purifying agent. The preparation method of the 
rare earth yttrium air purifying agent comprises the following steps: preparinga 
chlorine dioxide solution, putting the 
chlorine dioxide solution into a PE 
plastic bottle, putting an activating agent, a 
controlled release agent and gel into a glassware, stirring uniformly, pouring the uniformly stirred 
reagent into the 
chlorine dioxide solution in the PE 
plastic bottle after stirring for 5 to 8 minutes and when the color of the 
reagent is uniform, automatically diffusing thereagent in the solution to mix without stirring to be gel-like, covering the 
bottle cover, reserving an air-permeable 
small hole, putting at the cool and ventilation place indoors and standing; afterstanding the gel-like 
reagent for 1 to 2 days to be soft 
solid, taking out the 
solid, putting into a high-pressure micropulverizer, and 
grinding into 
powder with the grain size being 5 to 20 nanometers; adding 
activated carbon powder and photocatalyst 
powder into the prepared powder, jointly pouring into a three-dimensional mixing 
machine and mixing uniformly; and adding 
yttrium oxide, Pt powderand Rh salt into the uniformly mixed powder, adding water to stir until a viscous object occurs and packaging by a vacuum sealing mode.