The transformer coupling novel solid state fault current limiter（SSFCL） could limit the fault current effectively， while its volume and cost could be reduced by probably designing the coupling transformer. A methodology is proposed for designing the saturated coupling transformer in transformer coupling novel SSFCL. Firstly， the scheme for the coupling transformer with winding turns given is acquired， by applying field-circuit coupling finite element analysis（FEA） method and design of the air-core reactor; secondly， based on the premise of the same current limiting level， the change law of the leakage reactance voltage drop in the normal state and the secondary winding voltage in the open-circuit limiting state with the core radius is achieved; finally， the optimal result is obtained by curve fitting and optimization. The validity of the design method proposed is verified by the experiment of the small-scaled prototype.