The invention discloses a refuse incineration plant percolate treatment system, which comprises a coagulating sedimentation device, a biochemical device, a settling pond and a sludge concentration pond which are connected in series in turn, wherein the coagulating sedimentation device comprises a grid/grit chamber, a regulation pond and a reaction sedimentation pond, which are connected in turn in series; the biochemical device comprises an intermediate water pool, an upflow anaerobic sludge blanket (UASB) reactor, a secondary anacrobic/oxic (A/O) pond, a membrane bioreactor (MBR), a Fenton-electrochemical reactor and an aeration biological fluidized tank (ABFT), which are connected in series in turn; and the sludge in the reaction sedimentation pond, the UASB reactor, the MBR, the Fenton-electrochemical reactor and the settling pond is conveyed to the concentration pond. In the invention, the combined operation of the coagulating sedimentation pond, the UASB reactor, the secondary A/O pond, the MBR, the Fenton-electrochemical reactor and the ABFT is adopted, the ammonia nitrogen and organic matters in the percolate can be removed effectively, the amount of the concentrated liquidis reduced, the service life of the system is prolonged and the operation cost of the system is reduced.