Vulcanized eucommia ulmoides gum modified asphalt（VEUGMA） was prepared by natural plant-based eucommia ulmoides gum（EUG）， and the microstructure and pyrolysis process of VEUGMA were studied. The results show that VEUGMA is of lower penetration， higher softening point， larger ductility and viscosity， better deformation resistance at high temperature and cracking resistance at low temperature than matrix asphalt. Compared to matrix asphalt， VEUGMA has larger number and smaller size of honeycomb structures， lower root mean square roughness， greater adhesion， higher pyrolysis temperature， and less CO₂ and CO release. The modification effect is the best when 6% EUG and 3.5% sulfur （calculated by EUG quality） are added to the matrix asphalt.