目的 在氯化胆碱–乙二醇(ChCl–2EG)低共熔溶剂(DESs)中，以水为添加剂，采用电沉积制备Zn–Fe合金镀层，改善镀层的表面形貌，优化晶型结构，提高镀层的耐蚀性能。方法 采用电导率仪、黏度计、循环伏安曲线(CV)研究水含量对低共熔溶剂黏度、电导率、电化学窗口的影响。采用扫描电子显微镜(SEM)、能谱仪(EDS)，研究水含量对镀层表面形貌和成分的影响。采用X射线衍射仪(XRD)，分析水含量对镀层结构特征的影响。采用动电位极化曲线和电化学阻抗谱(EIS)，分析水含量对镀层耐蚀性能的影响。结果 随着水含量的增加，DESs的黏度降低，电导率升高，镀速增大，镀层中Zn含量提高，平均晶粒尺寸减小。当水的质量分数小于8%时，水会促进Zn和Fe的沉积。当水的质量分数大于8%时，水会抑制Zn和Fe的沉积。此外，当水的质量分数为4%时，DESs能够保持原有的电化学窗口(2.47 V)，制备的Zn–Fe合金镀层平整致密，镀层极化电阻达到最大值(1 469 Ω/cm²)，电荷转移电阻达到最大值(612 Ω/cm²)，耐蚀性最佳。结论 水的含量会影响DESs溶剂的黏度、电导率及电化学窗口，会影响Zn–Fe合金镀层的表面形貌、晶粒尺寸及耐蚀性。当加入质量分数4%的水时，不仅能够促进Zn和Fe还原，而且还能改善Zn–Fe合金镀层的表面形貌，提高镀层的耐蚀性能。

Due to the wide electrochemical window and the excellent stability, deep eutectic solvent has been considered as an ideal solvent for electrodepositing Zn-Fe alloy coating. However, deep eutectic solvent has high viscosity and low conductivity at room temperature, resulting in low electrodeposition efficiency. Therefore, the work aims to solve the problems of high viscosity and low conductivity of deep eutectic solvent with water as an additive, so as to improve the surface morphology of the Zn-Fe alloy coating, optimize the crystal structure and improve the corrosion resistance of the coating. Conductivity meter, viscometer and cyclic voltammetry (CV) were used to study the effect of water content on the viscosity, conductivity, and electrochemical window of deep eutectic solvent. Scanning electron microscope (SEM) and energy spectrometer (EDS) were used to investigate the effect of water content on the surface morphology and composition of the Zn-Fe alloy coating. X-ray diffractometer (XRD) was used to analyze the effect of water content on the structural characteristics of the Zn-Fe alloy coating. Potential polarization curve and electrochemical impedance spectroscopy (EIS) were used to analyze the effect of water content on the corrosion resistance of the Zn-Fe alloy coating. When added to deep eutectic solvent, water replaced choline chloride and formed a new hydrogen bond system with ethylene glycol. The substituted choline chloride existed in the form of choline ion, which promoted the dissociation of deep eutectic solvent. Therefore, with the increase of water content, the viscosity of deep eutectic solvent decreased, the conductivity increased, the content of Zn element in the Zn-Fe alloy coating increased, the average grain size decreased, and the corrosion resistance of the coating firstly increased and then decreased. When the water content in deep eutectic solvent was less than 8wt.%, the water could promote the deposition of Zn and Fe. When the water content was greater than 8wt.%, the water could inhibit the deposition of Zn and Fe. In addition, when the water content was 4wt.%, the deep eutectic solvent could still maintain the original electrochemical window (2.47 V), the Zn-Fe alloy coating had a smooth and compact surface morphology, the polarization resistance of the coating reached the maximum value (1 469 Ω/cm2), the charge transfer resistance reached the maximum value (612 Ω/cm2) and the corrosion resistance was the best. Water content affects not only the viscosity, electrical conductivity and electrochemical window of DESs, but also the surface morphology, grain size and corrosion resistance of Zn-Fe alloy coating. When the content of water in deep eutectic solvent is 4wt.%, the water can not only promote the co-deposition of Zn and Fe, but also improve the surface morphology and crystal structure of the coating, thus strengthening the corrosion resistance.