The invention discloses a waste fly ash washing water recycling treatment process which comprises the following steps: waste fly ash washing water preheating, evaporation and concentration, forced-circulation evaporation, concentrated solution circulation, sodium chloride crystallization, sodium salt-separating mother solution circulation and potassium chloride crystallization. Separation of sodium chloride and potassium chloride in the waste fly ash washing water is realized, the sodium chloride salt and potassium chloride salt are respectively obtained, production of solid wastes and hazardous wastes is reduced, the resource recovery effect is achieved, and the process is high in degree of automation, possible in continuous operation and high in production efficiency. In addition, a mechanical steam re-compression technique with energy conservation is used in the process, the energy consumption for evaporating one ton of water only accounts for 1/6-1/5 of that of a conventional evaporator, high thermal efficiency and low energy consumption can be achieved, pollutants can be reduced, and environment pollution can be avoided. The invention further discloses equipment of the process, dependency to boiler equipment can be reduced, environment pollution can be reduced, energy conservation and environment protection can be achieved, a high equipment automation degree can be achieved, and the process adopts equipment with continuous operation and production and is high in efficiency and low in operation cost.