The invention provides a salt separating crystallization process. The salt separating crystallization process comprises the steps that brine passes through a nanofiltration membrane to obtain nanofiltration transmission liquid and nanofiltration concentrated liquid; the nanofiltration transmission liquid and the nanofiltration concentrated liquid pass through membrane concentration equipment to obtain contributing water and concentrated water; the concentrated water enters an evaporation system for concentration and crystallization; crystals are dehydrated and dried, and pure salt or anhydrous sodium sulfate is obtained. According to the process, the high-purity salt and anhydrous sodium sulfate can be extracted from hard-to-treat strong brine in a sewage treatment station, waste water recycling is achieved, and the advantages of being short in process, centralized in equipment, small in occupied area and low in energy consumption are achieved.