The invention discloses a high-performance phenol-aldehyde amine curing agent used for epoxy resin and a preparation method thereof and relates to a phenol-aldehyde amine epoxy resin curing agent which is a low-viscosity epoxy resin curing agent applicable to low-temperature damp construction. The curing agent comprises the main components with the weight percentage as follows: 36-45 percent of phenol, 5-8 percent of long-chain phenol, 18-22 percent of formaldehyde solution, 20-25 percent of ethylene polyamine, 3.5-5.5 percent of 4, 4'-diminodiphenyl-methane and 1.5-2.5 percent of polyphenyl polyamine methane. The invention uses a form of normal pressure reaction, thereby avoiding the risk of high temperature and high pressure synthesis; the production method is simple; the curing agent has high activity, low viscosity, good construction and high intensity, so the curing agent can overcome the disadvantages that the epoxy resin is cured slowly under low temperature and has low intensity later. A cured product obtained by curing the epoxy resin with the curing agent overcomes the disadvantage of the brittleness of ordinary phenol-aldehyde amine. The phenol-aldehyde amine epoxy resin curing agent is applicable to the fields of building reinforcing, bridge reinforcing, sealing bonding, water conservancy project, antiseptic paint, etc.