In view of the characteristics and disadvantages of the application of asphalt rubber in road engineering, different concentration of silane coupling agent（KH550） solution was used to treat the surface of crumb rubber modifier. Through high temperature performance, low temperature performance, temperature sensitivity and compatibility test, it was determined that the reasonable concentration（by mass） of KH550 solution for surface treatment of crumb rubber modifier was 1.0%. Surface properties of the crumb rubber modifier after treatment was studied by scanning electron microscopy test. Meanwhile, the micro modification mechanism of modified asphalt rubber was analyzed by infrared spectrometer. Through the comparison of the performance and economic benefit of modified asphalt rubber and SBS modified asphalt, the results show that surface treatment of crumb rubber modifier can significantly improve the high temperature performance of asphalt rubber, and has good economic benefits.