In order to develop a high viscosity modified asphalt for drainage pavement, styrene-butadiene-styrene block copolymer (SBS), styrene-butadiene rubber (SBR), rubber powder and sulfur powder were combined to prepare a high viscosity modified asphalt (HVMA-4), and three common high viscosity modified asphalt were compared as control group. Zero shear viscosity test, dynamic rheological test and bending rheological test were used to evaluate the viscosity, high temperature and low temperature properties of the HVMA-4 composite modified asphalt and the control group, respectively. The structure and microstructure of the composite modified asphalt were analyzed by infrared spectroscopy and scanning electron microscopy. The results showed that HVMA-4 had the best high-temperature rheological properties, with 93.9%, 82.1% and 68.8% improvement at 68 ℃ over HVMA-1, HVMA-2, and HVMA-3, respectively. HVMA-4 showed more outstanding rutting resistance, low temperature cracking resistance and permanent deformation resistance. The microscopic results showed that the three modifiers were uniformly distributed in asphalt and form a three-dimensional network structure. The formation of HVAM-4 had both physical and chemical changes, and the intermolecular stability of asphalt was improved.