The invention discloses a shale gas produced water treatment system and method. The system comprises a filter, a preheating unit comprising a heat pre-exchanger, a raw water tank and a water feeding pump, a circulating evaporation unit comprising a circulating heat exchanger, a first evaporation crystallizer, a circulating pump and a three-way valve, and a recovery and heat exchange unit comprising a compressor and a stripping tower. The method comprises filtering to remove impurities in raw shale gas produced water, pre-heating the water to 50-90 DEG C, re-heating the pre-heated raw water to 95-130 DEG C through steam obtained by evaporative crystallization, and pre-heating the filtered raw water through the condensate water obtained by re-heating. The circulating evaporation unit realizes circulating evaporation crystallization on the shale gas produced water so that a treatment process is shortened. The recovery and heat exchange unit orderly re-heats and pre-heats the raw water to be subjected to evaporation crystallization through steam formed by evaporation crystallization in the first evaporation crystallizer so that the energy use rate of evaporative crystallization is improved and energy consumption is reduced.