Abstract: According to the characteristics of plaster brine，the lime，mother liquid，and flue gas were taken to purify it.The obvious effect of plaster brine purification by flue gas was proved through a series of data got from purification mechanism， laboratory experiment，site amplification experiment，and production operation.The index of the refined brine was very high， which is favorable for the later salt production.This technology successfully realized energy saving and emission reduction and it obtained obvious economical，social，and environmental protection benefits.Therefore，it is worthy to be promoted.

Key words: flue gas, brine purification, plaster brine, technology application