The nano composite waterborne epoxy coating was prepared by a self-emulsifiable waterborne epoxy curing agent and epoxy resin.The self-emulsifiable curing agent was synthesized by TETA(triethylene tetramine) and the ending agents with nano-SiO_2.The emulsification properties of the curing agent and the coating properties were changed with different ending agents and different contents of nano-SiO_2.The results suggested that curing agent and coating with expected properties can be prepared with phenyl glycidylether and the benzyl glycidylether as the ending agent and 2% nano-SiO_2.