Firstly we analyzed the effect of the type of matrix asphalt, the dosage of SBS modifier and shear time on the properties of SBS modified asphalt with the analysis method of Multi-factor, then we analyzed the mechanism of interaction between SBS modifier and matrix asphalt based on the four-component test analysis. The results showed that different types of matrix asphalt had different modification effect. Among them, the matrix asphalt A and SBS modifier had the best compatibility. The high content of asphaltene helped to improve the temperature properties of asphalt, the asphalt with high content of aromatic was much easier to be modified. As the dosage of SBS modifier reached 4.2%, the interconnected network had been formed, the modification effect achieved the optimal result, but the modification effect would be reduced with an additional contribution of SBS modifier. With the prolonged shear time, SBS modifier could be dispersed in the matrix asphalt more uniformly, however, the shear time should not be too long, the optimum shear time is 40min.