To study effects of the compound amino acid fertilizer synergist(CAAFS) on the growth,yield and nutrients uptake of cotton on a salt affected soil,pot experiment was tested with cotton in Xinjiang.The results showed that compared with common water soluble fertilizer,adding the CAAFS promoted the leaf SPAD value of different growth periods of cotton,and improved the yield of seed cotton by 32.19% and cotton fibre by 41.49%;improved dry matter accumulation of all growth periods of cotton on the ground,and significantly improved the partial fertilizer productivity and agronomy efficiency by 54.22% and 32.48%，respectively,which explained that CAAFS significantly reduced the fertilizer nutrient loss.In short,CAAFS had good fertilizer effect on cotton on salt affected soil,which deserved further study and popularization.