An epoxy mortar material for a bridge expansion joint structure and a construction method thereof are provided. The epoxy mortar material includes a liquid A, a liquid B and a filler, wherein diamines D2000 and D230 are mixed to act as the epoxy resin curing agent. The curing agent has low viscosity, good compatibility with epoxy resin, long usable life, high bonding strength, and good flexible and heat shock resistance, so that it is suitable for the epoxy mortar material capable of absorbing the stress. Furthermore, the silicone adhesive is made into the sealing waterstop band, so that the present invention has good water resistant performance; the color of the expansion joint structure is the same as that of the adjacent concrete or asphalt, so that the bridge has beautiful appearance; the expansion joint structure has no tremors while vehicles passing through, noise generated by vehicle driving is lower.