In the highway tunnel, the asphalt pavement will be used more and more common, and the corresponding fire-retardant asphalt technology research and application is still lacking. In the future, the study should be focused on the special asphalt flame retardant and the processing technology research. Using flash point and ignition point could not distinguish the combustion ability between different types of asphalt with different amount of flame retardant. The oxygen index method could evaluate the sustained combustion performance of asphalt. Based on the oxygen index method used in textiles, put forward a primary oxygen index test method for asphalt. The asphalt flame-retardant evaluation method and standard also should be further refined and adjusted in the future research and application. From the performance test results, it could be found that the addition of fire-retardant is benefit for the pavement-performance of asphalt. For the Magnesium hydroxide agent, the amount of 8% could result in compositive optimal performance of asphalt.