Abstract: This field experiment studied the effects of flue gas desulphurization by-product gypsum and irrigation on soil salt content and oil sunflower yield. The results showed that the treatment with 10 t flue gas desulphurization by-product gypsum per hm2 and 3 900 m3 water per hm-2 had best desalination effect, and the desalination rate of upper layer of soil increased with increased irrigation amount. Under the conditions of application of 10 t flue gas desulphurization by-product gypsum per hm2 and 3 900 m3 per hm-2 of irrigation amount, soil salt content in the soil was the lowest, and germination rate and yield of oil sunflower were the highest．

Key words: oil sunflower, soil salt content, flue gas desulphurization by-product gypsum, irrigation amount