Nano-TiO2 dispersion liquid was prepared in deionized water with ultrasonic methods by using nano-TiO2 as the raw material, and selecting sodium hexametaphosphate (SHMP), Tritor-X-100, polyethylene glycol (PEG) 400, sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS) and cetyl trimethyl ammonium bromide (CTAB) as the dispersants. The absorbance of the sample was measured by UV-Vis spectrophotometer, and the influence of the ultrasonic time, the type and concentration of the dispersant on the stability of the sample was analyzed, and the optical performance of the sample was tested. The results of the study show that, stable nano-TiO2 dispersion liquid can be obtained by adding SHMP and ultrasonic treatment for 35 minutes with an absorbance of about 0.1, and under the illumination of the light source (CCT=10000K), the Rayleigh scattering effect of the simulated sky light can be achieved.