In order to explore the absorption differences of different zinc fertilizers foliar spraying to winter wheat in the potential zinc deficiency area of the Loess Plateau, the spraying period of the best absorption effect was determined. Field experiment was set in the potential zinc deficiency area of the Loess Plateau. There are six treatments of control; spraying ZnO NPs at the jointing stage; spraying bulk ZnO , ZnSO₄ and ZnO NPs at jointing stage and filling stage; spraying ZnO NPs at jointing stage, heading stage, flowering stage and filling stage . The results showed that there were no significant differences in grain yield, panicle number and 1000-grain weight of winter wheat. Among all treatments, there were no significant effect on trace elements such as Mn and Cu in wheat grains, but had a significant effect on Zn and Fe content. Compared with CK, the spraying of zinc fertilizer significantly increased the zinc content of grain. The effect of spraying zinc with different zinc fertilizers in the same period was in ZnO NPs, reaching 30.48 mg·kg ^-1 , which was 70% higher than that of control. Followed by ZnSO₄, which was 28.41 mg·kg ^-1 . which was 58 % higher than that of control. The bulk ZnO was the lowest, reaching only 21.6 mg·kg^-1, which was 20% higher than the control. The zinc content of grain treated with ZnO NPs in four periods was 40.20 mg·kg ^-1, which reached the recommended value for the zinc content of wheat grains. Bulk ZnO and ZnSO₄ did not cause significant differences in Fe content in winter wheat, but ZnO NPs treatment significantly increased grain Fe content and decreased with increasing application rate. With the increase of spraying times, the zinc contents of stems and leaves of each treatment were significantly higher than that of control, but the transfer efficiency from leaf to stem was low. The zinc content in the leaves treated with ZnSO₄ during the filling period was 21.87 mg·kg ^-1 , and the ZnO NPs treatment in the same period reached 58.46 mg·kg ^-1 , an increase of 167%. There was no significant difference in grain N P K content between the treatments. Synchrotron radiation X-ray technology proved that spraying ZnO NPs four times greatly increased the zinc content in the aleurone layer of wheat grain, which provided a good foundation for the targeted zinc improvement.