In order to reveal the photosynthetic physiological response mechanism for winter wheat under brackish water irrigation, a two-year field test was conducted in Yellow River Delta（2015—2016 and 2016—2017）, Shandong Province, North China. Two irrigation treatments (irrigating 80mm with fresh water each at jointing, heading and milking stages, and irrigating 80mm with fresh (0g/L)- saline (3g/L)-saline(3g/L) water each at jointing, heading and milking stages) were designed. Test items included transpiration rate, net photosynthetic rate and stomatal conductance at the heading and flowering stages of winter wheat. Stomatal limitation and non-stomatal limitation values of leaf photosynthesis were calculated, meanwhile, changes of winter wheat leaf photosynthetic parameters of light response curve were observed. The results showed that in comparison with fresh water irrigation (CK), brackish water irrigation resulted in a significant increase of 37.8% and 64.3% of salt content in shallow soil layer (0~40cm) in 2016 and 2017, respectively, inhibited the transpiration at heading and flowering stages of winter wheat. Transpiration rate was decreased by 19.1% and 31.4% at heading stage, and by 11.6% and 11.0% at flowering stage in 2016 and 2017, respectively, the net photosynthetic rate was decreased before noon in the day, in which stomatal factors and non-stomatal factors inhibited leaf photosynthesis of winter wheat, but it can increase net photosynthetic rate in the afternoon, with a higher stomatal limitation value indicated that the non-stomatal factors were improved. The modified rectangular hyperbolic model of light response were introduced to obtain the photosynthesis parameters, the maximum net photosynthetic rate (Pnmax) of winter wheat under brackish water irrigation in 2015—2016 were increased by 2.27μmol/(m2·s) and 1.58μmol/(m2·s) at the heading and flowering stages, respectively, light saturation point (LSP) were increased by 29.27μmol/(m2·s) and 70.11μmol/(m2·s), light compensation point (LCP) was decreased by 19.38μmol/(m2·s) and 4.63μmol/(m2·s), dark respiration rate (Rd) was decreased by 0.96μmol/(m2·s) and 1.53μmol/(m2·s) compared with fresh water irrigation, while in 2016—2017, the maximum net photosynthetic rate (Pnmax) under brackish water irrigation were increased by 1.12μmol/(m2·s) and 1.83μmol/(m2·s) at the heading and flowering stages respectively, light saturation point (LSP) were increased by 15.07μmol/(m2·s) and 19.9μmol/(m2·s), light compensation point (LCP) was decreased by 7.87μmol/(m2·s) and 18.8μmol/(m2·s), dark respiration rate (Rd) was decreased by 3.33μmol/(m2·s) and 5.17μmol/(m2·s) compared with fresh water irrigation, it was showed that the saline water treatment enhanced the adaptability against strong light and high temperature conditions at the heading and flowering stages, promoted the ability using weak light of winter wheat. Therefore, brackish water irrigation did not negatively affect leaf photosynthesis in heading and flowering stage of winter wheat, but promoted the potential of utilizing light energy of winter wheat to some extent.