Treatment system and treatment method of catalytic cracking desulfurization waste water

The invention provides a treatment system and treatment method of catalytic cracking desulfurization waste water. The method comprises the following steps: performing concentration treatment on the catalytic cracking desulfurization waste water to obtain concentrated liquid, and performing spray drying on the concentrated liquid under 320 to 380 DEG C to obtain sodium sulfate crystals. The treatment system comprises a concentration unit and a spray drying unit in sequential connection. According to the invention, low-temperature site heat of petrochemical enterprises is mainly utilized to pre-concentrate desulfurization waste water externally discharged in a wet method washing process of a catalytic cracking device; after pre-concentration, the waste water is sprayed into high-temperatureflue gas extracted from a denitration section of a catalytic cracking waste heat boiler; spray drying is performed; salt crystals after spray drying are collected by a bag-type dust remover and are recovered; and the flue gas