In order to investigate the effects of residual film content on soil water-salt and crop growth in cotton field under drip irrigation, eight treatments of residual film contents, 150 (T1), 230 (T2), 465 (T3), 857 (T4), 1 250 (T5) and 1 640² kg/hm (T6), original soil (CK1) and no residual film control (CK2), were set in a cotton field. The effects of residual film contents on soil water-salt, soil and crop root nitrogen and yield in drip irrigated cotton field were analyzed. The results showed that with the increases of residual film contents, soil water contents decreased gradually, and the enrichment effect of soil salt increased gradually. The variation degree of soil water and salt was positively correlated with the residual film content in 0-40 cm soil layer, and the Coefficient of variation CV of soil water and salt in T5 and T6 was significantly larger, the CV of water content was 0.52 and 0.44 and salt was 0.34 and 0.31 respectively. The nitrogen contents in soil increased with the increases of residual film contents, and the total nitrogen contents in root were negatively correlated with the residual film contents. The yield of cotton decreased gradually with the increases of residual film contents. When the residual film content was more than 230 kg/hm², the decline was significantly enhanced, compared with CK2, the yield of T3, T4, T5 and T6 decreased by 14.19%, 21.69%, 29.19% and 37.29% respectively. This study could provide theoretical basis and scientific support for the sustainable development of mulched drip irrigation cotton field and the prevention and control of residual film pollution in Xinjiang.