The utility model relates to a transformer iron-core tensile plate locking structure, which belongs to the technical field of transformer manufacturing. The technical scheme includes that the iron-core tensile plate locking structure comprises a fixing bolt (1), a base plate (2), a locking plate (3), a tensile plate (4) and a web plate (5), the tensile plate and the web plate are fixed integrally via the fixing bolt, the base plate is arranged between the fixing bolt and the web plate, and the locking plate is disposed between the base plate and the fixing bolt. The iron-core tensile plate locking structure has the advantages of overcoming looseness between the iron-core tensile plate and the web plate when a transformer is in drying treatment, hoisting, transporting and running, avoiding local overheating or electric discharging, avoiding generating gas due to transformer oil decomposition caused by overheating, and being capable of effectively locking the iron-core web plate and the tensile plate and guaranteeing stable running structure thereof. The iron-core tensile plate locking structure is adaptable to transformers with various capacities.