Large stone porous asphalt mixes have well drainage ability, as well as higher modulus and durability when used as base course. Large stone porous asphalt mixes have good effect on repairing the semi-rigid base course which have longitudinal cracks. It not only can delay the reflection of cracks, but also plays the role of excluding water in structural layer owing to relatively large porosity. Deflection value of upper base's top surface decreases and deflection difference between left and right wheel track reduces after paving large-stone asphalt mixes upper base. When there are longitudinal cracks in lower base course, top surface tensile stress of upper base(large-stone asphalt mixes flexible upper base course)has significantly reduced compared with semi-rigid base course upper base. And maximum shear stress declined slightly. It can play a very well crack resistance effect when using large-stone asphalt mixes to repair broken cement stability upper base.