The invention discloses a preparation method of a colored micro-surfacing based on nano titanium dioxide slurry. The preparation method comprises the following steps: S1: selecting nano titanium dioxide powder; S2, preparing a dispersion liquid, and adding the dispersing liquid into a dispersing machine; S3, starting the dispersing machine, slowly adding the nano titanium dioxide powder into a dispersing tank of the high-speed dispersing machine at a low-speed state, increasing the dispersion speed, and carrying out dispersing at a high speed of 8000 rpm; and S4, carrying out particle size detection on the product obtained in the step S3, wherein the colored micro-surfacing based on the nano titanium dioxide slurry is obtained after the particle size is detected to be qualified. Accordingto the invention, a colored pavement is rapidly repaired through a colored micro-surfacing technology, meanwhile, PM2.5 particles and harmful gas in tail gas can be efficiently adsorbed, and harmful substances in the tail gas are decomposed into non-toxic nitrates and carbonates under the action of light, so that the colored micro-surfacing has the advantages of low cost, convenience use, safety,no toxicity, long-term use and the like.