A new digital testing equipment for pavement materials was developed. By using this equipment, the erosion performance for 3 types of semi rigid base materials with 7, 28 and 90d were studied. The relationship among standard erosion times, hydrodynamic pressure and splitting strength were established. It is found that with the increase of aging time, the anti erosion factor decreased, whereas the erosion stress ratio index changed slightly, the mean value is about 18, and both the aging time and hydrodynamic pressure have insignificant influence on the erosion depth index, the average is around 1.8. The experimental results show that freezing and thawing have little effects on the anti erosion factor and erosion stress ratio index of the material, the drop of erosion resistance performances of base material can be attributed to the decrease of the structure strength. Moreover, the splitting strength of semi rigid base material which can better reflect the bond effect of mortar rather than its compressive strength is much more closely related to its erosion resistance performance.