The invention discloses an antibacterial negative ion lead and cadmium free low temperature frit and a preparation method thereof. The preparation method comprises the steps of: A. material mixing: mixing and grinding 10-18% of quartz, 5-12% of feldspar, 15-25% of borax, 3-12% of carbonate, 20-35% of boric acid, 3-8% of spodumene, 1-4% of fluoride salt, and 0-5% of kaolin evenly, then adding 1-5% of an antibacterial compound and 3-8% of a negative ion compound, and grinding the substances uniformly to obtain a mixture; B. melting; and C. molding and cooling. Compared with the existing low temperature frits, the low temperature frit prepared by the method provided by the invention has the advantages of scientific compounding, reasonable preparation, stable performance, and no lead, cadmium or other extremely toxic substances. Also through reasonable collocation of the negative ion compound and the antibacterial composite material, the two play a synergistic role and endow the frit with excellent antibacterial and air purification characteristics, thus further broadening the application scope of the low temperature frit. And the low temperature frit can be used as the raw material to manufacture abundant building materials, like antibacterial negative ion mosaics, antimicrobial negative ion microcrystalline ceramic composite plates, and antibacterial negative ion low temperature ceramic ink, etc.