The content of iron in alkaline calcination soil at the eastern foot of Helan Mountain is insufficient and the availability is poor，which can easily lead to the phenomenon of chlorosis of grape due to iron deficiency，thus reducing the quality and yield of wine grape. The application of iron fertilizer can meet the demand of wine grape for iron nutrition，but the appropriate amount of iron fertilizer to achieve high quality and high yield of grape is not clear. Taking 6-year-old Cabernet Sauvignon as the research object，five different levels of chelated iron spray were set up: 0.86 kg/hm²(T1)，1.14 kg/hm²(T2)，1.43 kg/hm²(T3)，1.73 kg/hm²(T4)and 2.0 kg/hm²(T5)，using spray water as a control(CK)，to study the effect of foliar iron supplementation on production，physiological regulation and quality improvement of wine grapes. The results showed that the photosynthetic rate，intercellular CO₂ concentration，transpiration rate and total chlorophyll content of the leaf surface treated with iron chelate were significantly increased compared with those treated with CK，and T3 was the highest. The photosynthetic rate，intercellular CO₂ concentration，transpiration rate and total chlorophyll content of the leaf treated with iron chelate increased by 10.3% ～ 17.8%，4.4% ～ 14.9%，8.6% ～ 41.6% and 11.0% ～ 16.7%，respectively，compared with those other treated with iron chelate；Stomatal conductance was the highest in T3 and T4 treatment，which increased by 15.5% ～ 106.5% compared with other treatments. At the same time，the yield of Fe-chelated fertilizer treatment was 7.4% ～ 21.6% higher than CK treatment. The content of anthocyanin in fruit was the highest in T3，which increased 112.1% compared with CK，and increased 8.5% ～ 31.2% compared with other treatments of iron chelate spraying. In short，in the wine producing areas at the eastern foot of Helan Mountain，iron fertilizer applied on the leaves can effectively promote the photosynthetic capacity of wine grapes and promote the improvement of berry quality. When the amount of chelated iron applied on the leaves is controlled at about 1.43 kg/hm²，the yield and quality of wine grapes can be improved most effectively.