A method to simulate the transient process of interturn short-circuit fault of converter transformer based on field-circuit coupling mthod is presented, which can effectively solve the complex electromagnetic problems in the process of short-circuit fault, and obtain the short-circuit current waveforms of line ends and windings in the process of fault. An interturn short circuit case in a converter transformer is used for simulation calculation, the occurrence of short circuit fault is simulated by setting the switch closing time in the external circuit, and the fault current waveform at the line end is obtained by combining the system parameters and the initial phase angle of the fault time. The calculated waveform is basically in agreement with the actual fault recording waveform, which verifies the hypothesis of fault development process and shows that the proposed method is applicable to the transient simulation of transformer interturn short-circuit fault.