The invention discloses a dication asphalt emulsifier. The molecular structure of the dication asphalt emulsifier is shown in the description, wherein when x is equal to 1, y is equal to 1 and i is equal to 0; when x is equal to 2, y is equal to 0, z is equal to 1 or 0, and i plus z is equal to 1. The dication asphalt emulsifier is prepared from the following raw material in molar ratio: 1 mol of N-Hydrogenated tallow-1, 3-diaminopropane, 6.00-13.00 mol of alcohols solvent, 1.02-3.05 mol of methyl acrylate, and 2.02-2.10 mol of sodium chloroacetate. The alcohols solvent adopts ethyl alcohol, methyl alcohol or isopropyl alcohol. The synthetic raw material of the dication asphalt emulsifier is easy to get, the production cost is low, the technology is simple, and high-temperature reaction is not required. Different types of asphalt can be emulsified, the prepared asphalt emulsifier is exquisite and uniform, the storage stability is good, dication emulsified asphalt can be prepared, and the dication asphalt emulsifier is applied to spreading of road penetrated oil layers or bonding oil as well as slurry surfacing and micro-surfacing parts, and has the characteristics of a medium breaking asphalt emulsifier and a slow breaking asphalt emulsifier.