目的 研究对比了3种不同配方Al-Zn-In合金阳极在南海环境条件下的腐蚀形貌及电化学容量、电化学效率等性能参数，为深海工程装备的阴极防护设计提供可靠的参考依据。方法 通过在我国南海1 200 m深海试验架上搭载阳极阴极保护测试装置及数据采集、存储系统，采用自放电测试(Free Running Test，FRT)试验方法研究了阳极在110 d长周期条件下的电化学性能，采用超景深三维显微镜对其表面腐蚀形貌进行了观测。结果 1#—3#阳极下水后工作电位均快速活化，整个试验阶段，平均工作电位分别为?1.029、?1.033、?1.098 V(Ag/AgCl/海水);电化学效率分别为81.62%、78.02%、87.90%。仅自主设计的3#配方阳极的开路电位和电化学效率达到了UNE-EN 12496-2013阴极保护设计标准的要求。结论 与模拟深海环境下的恒电流测试(Galvanostatic Test，GST)短期试验(4 d)结果相比，同一配方阳极在深海110 d长周期FRT测试条件下的电化学效率分别降低15.13%，18.87%和8.14%。长周期FRT试验更接近实际阳极服役状态，可为深海阴极保护设计参数选择提供可靠性参考。相较于1#和2#阳极，3#阳极In元素增加了1倍，使得工作电位更负，溶解区域晶粒细化，电化学效率更高。但是3#阳极表面却发现了局部未溶解区域。可见，仅通过增加In含量对于改善铝合金表面腐蚀形貌效果有限。

Sacrificial anode cathodic protection is one of the most important corrosion protection methods for deep-water steel structures. The electrochemical performance of sacrificial anode in deep-water environment directly affects the protection effect and service life of the facilities. By means of the cathodic protection test device and data acquisition/storage system installed on the 1 200 m Deepwater test rack in the South China Sea, the free Running Test (FRT) was applied to study the electrochemical performance of sacrificial anode under the 110 days cycle condition. Solution morphology, electrochemical capacity, current efficiency and other performance of 3 kinds of composition Al-Zn-In-based sacrificial anodes were compared under the environmental conditions in the South China Sea, providing a reliable reference for the cathodic protection design of deepwater subsea engineering facilities.