The modified emulsified asphalt with different dosages of water-based tackifying resin is prepared. The conventional properties of emulsified asphalt evaporated residue, the mechanical properties of interlayer adhesion and the phase structure with the change rule of resin dosage are studied. The pavement performance of the emulsified asphalt modified by water-based tackifying resin is evaluated and the optimal dosage of resin is determined. The results show that the water-based tackifying resin can improve the stability of emulsified asphalt at high temperature and increase the resistance to bond failure and shear failure between layers. But it has an adverse effect on the low-temperature ductility. With increase of tackifying resin dosage, the modified emulsified asphalt system gradually forms a dense cross-linked network structure. However, when the dosage is 25%, there is a risk similar to polymer agglomeration, and serious low temperature cracking resistance attenuation occurs. It is suggested that the dosage of water-based tackifying resin should be 15%~20% in actual projects.