The research was aimed to explore the effects of spraying different concentrations of exogenous zinc on the zinc content，zinc bioavailability，mineral element content and yield of millet during the booting stage，and to clarify the optimal application amount of exogenous zinc，and provide theoretical support for the rational application of zinc fertilizer in millet production.Jingu 21(conventional cultivar)and Zhangzagu 10(hybrids)were used as test materials，and same amount of 0(CK，clear water)，20(Zn1)，40(Zn2)，60(Zn3)，80(Zn4)，100(Zn5)mg·kg-1 zinc sulfate(ZnSO4·7H2O)were sprayed at the booting stage of millet.The effects of different concentrations of zinc on the zinc content in different parts of plants，zinc bioavailability，yield and quality of millet in booting stage were studied.The result showed that exogenous zinc significantly increased the zinc content of various parts of the plant，and with the increase of zinc spraying concentration，the zinc content continued to increase，and reached the maximum in the Zn5 treatment，and the content didn't exceed the national standard zinc content(<50 mg·kg-1).After applying different concentrations of exogenous zinc，the distribution ratio of zinc in leaves was the largest，followed by roots and stem sheaths，in grains it was the smallest.With the increase of zinc concentration，the phytic acid(PA)content and PA/Zn molar ratio of millet seeds decreased first and then gradually increased，and the decrease was the largest at 40 mg·kg-1 treatment.Compared with the control，the PA content and PA/Zn molar ratio of millet seeds of Jingu 21 decreased by 46.06% and 54.31% respectively，and those of Zhangzagu 10 decreased by 35.80% and 40.31%，respectively.After spraying with different zinc solutions，the contents of grain nitrogen，phosphorus，potassium and crude protein increased first and then decreased，and reached the highest level at 40 mg·kg-1.Compared with CK，the contents of grain nitrogen，phosphorus，potassium and crude protein increased by 9.26%，40.79%，9.20%，9.26% for Jingu 21，and increased by 5.36%，17.17%，4.58%，5.36% for Zhangzagu 10，respectively.Compared with CK，the panicle length，1000-grain weight，grain weight per ear and yield of millet with different Zn spraying concentrations and different cultivars were increased the most in Zn2 treatment，and they increased by 7.12%，3.79%，20.69%，21.16% for Jingu 21，and increased by 3.33%，5.16%，14.22%，13.94% for Zhangzagu 10，respectively. In conclusion，exogenous zinc plays an important role in the zinc content，bioavailability，quality improvement and yield increase of millet.We suggest that spraying 40 mg·kg-1 zinc solution at the booting stage is the most reasonable for zinc-rich millet production and can achieve high yield and high efficiency.