An asphalt shear strength tester was developed. It had the advantages of high precision, low cost, and was easy to generalize. Interlayer shear strength testing scheme was designed based on the characteristics of vehicle real driving conditions. Considering different interlayer material types, three typical binding conditions were selected, i.e., "with binding oil", "without binding oil" and "geotextile + binding oil". For each kind of binding condition, four specimens were prepared to test the shear strength under different normal stress states. By comparing experimental results, the shear strength formulas for the three conditions were obtained.