Due to the insufficient anti-short-circuit ability of dry-type transformer, the interturn short-circuit fault of the dry-type transformer windings caused by the load side outlet short circuit in operation still occurs. In order to improve the sensitivity of real-time monitoring faults, it is urgent to study the transient characteristics of the dry-type transformer windings when the interturn short circuit fault occurs. The principle of "field-circuit" coupling is analyzed in this paper. Secondly, a two-dimensional "field-circuit" coupling simulation model is established with finite element software ANSYS that is consistent with the physical structure of the dry-type transformer, and the accuracy of the model under the rated operating conditions is verified. Moreover, the interturn short circuit fault occurs at different locations set by the external circuit of the coupling model and distribution characteristics of electromagnetic parameters is analysed when a single interturn short circuit fault occurs in the winding of dry-type transformer. Finally, the transient characteristics of electrical parameters such as the power loss factor and change rate of active power loss are obtained as sensitive characteristic state quantities, and the conclusion provides a theoretical basis for the real-time online monitoring of interturn short circuit faults in dry-type transformers and the improvement of winding anti-short circuit capability.