The invention belongs to the field of high temperature molten salt electrochemical analysis and test, and provides a zirconia electrode for detecting oxygen ions in high temperature molten salt. The zirconia electrode comprises an upper electrode fixing member, an electrode fixing ball, a lower electrode fixing member, and an electrode body. The electrode body mainly comprises a silver electrode lead, an upper sealing plug, a corundum pipe, a lower sealing plug, a zirconia pipe, and internal reference molten salt. The zirconia electrode has the advantages of simple structure, convenience for assembly, small volume, and light weight, can be used to detect the oxygen ion concentration of high temperature molten salt containing various contents, and can be used in a lab. The measuring result is accurate, the zirconia electrode is sensitivity, and the scaling range is large.