The invention relates to an antibacterial, mildewproof, self-cleaning, air cleaning and environment-friendly spray coating liquid, which comprises the following raw materials in percentage by weight: 0.5 to 20 percent of modified adsorbent, 0.1 to 10 percent of nano photocatalyst, 0.1 to 10 percent of binding and film forming agent, 0.01 to 5 percent of dispersant, and the balance of deionized water. The preparation method comprises that: photocatalyst powder is subjected to acid soluble treatment by inorganic strong acid and prepared into sol; adsorbent is immerged in a soluble salt mixture solution of antibacterial and mildewproof ions, subjected to ion exchange treatment and prepared into the modified adsorbent which is mixed with the binding and film forming agent and the dispersant; two types of solutions are mixed and a spray coating liquid precursor is obtained; and the antibacterial, mildewproof, self-cleaning, air cleaning and environment-friendly spray coating liquid is obtained after distributed processing and filtration. The antibacterial, mildewproof, self-cleaning, air cleaning and environment-friendly spray coating liquid can be applied to antibacterial, mildewproof and self-cleaning treatment of buildings or articles. The antibacterial, mildewproof, self-cleaning, air cleaning and environment-friendly spray coating liquid realizes synergetic and reinforced combination of three functions through the composition of multi-functional compositions, and the preparation method is simple and environment-friendly, has good industrial benefit and can realize industrialized production.