A curing agent and method for producing the same are provided, the method includes: esterification reaction: reacting a polyhydric alcohol with a polybasic acid anhydride to obtain an ester-based emulsifier (A); chain extension reaction: reacting an ester-based emulsifier (A) with a bifunctional epoxy resin to obtain a polymer intermediate (B); and reacting the polymer intermediate (B) with a polyamine compound to obtain a curing agent (C).