This study aimed to synthesize polystyrene (PS)-TiO2 nano-composite from the waste solid absorbent directly, so that the waste TiO2/PS solid absorbent could be used as nano-materials. TiO2 powder with a particle size of 12 nm was used for the solid absorbent. The TiO2 packed scrubbing tube was used for treating synthetic waste gas that contained styrene monomer. Experimental results confirmed that the concentrations of styrene in synthetic waste gas can be reduced by 62% after the activation of photocatalyst, and the lifetime of activated TiO2 catalyst is over 2 hours. From the NMR and DSC spectra of obtained products, PS is actually grafted on the surface of TiO2. The glass transition temperature of obtained PS in TiO2/PS solid absorbent is 100oC.