In order to realize the environmental protection requirement of "zero discharge" in the treatment of salty wastewater in coal chemical industry, after biochemical treatment, membrane separation and MVR concentration, the salty wastewater was entered into the double-effect forced evaporation system, and then the mixed salt solid was produced by evaporation and crystallization and treated as hazardous waste. The secondary steam condensate produced in the process could be used as the flushing water in the system or recycled back to the previous system; the condensed water after steam condensation was returned to the boiler room for reuse; the non condensable gas in the system was pumped out by the water ring vacuum pump and directly discharged into the atmosphere, and realized no discharge in the whole process.