Because the problem in automobile exhaust decomposition type pavement research, a Test systems of photocatalytic performance was establish, and Cumulative decomposition rate, average rate of decomposition, cumulative amount of decomposition and decomposition efficiency was built to evaluate the photocatalytic performance. SBS pitch modifier, asphalt, emulgator, stabilizer, Nano-TiO2, sodium hexametaphosphate and hydrochloric acid could be used to the preparation of photocatalytic slurry. The relationship between irradiance and photocatalytic performance was also research. The results show that Cumulative decomposition rate, average rate of decomposition, cumulative amount of decomposition and decomposition efficiency can estimate photocatalytic performance exactly, The relationship between irradiance and photocatalytic performance is in Non-linear relationship.