Abstract: Converter transformer system is an important equipment system in UHV converter station. Once damaged, it will cause serious loss of the electrical function and requires a lot of time to repair. Therefore, it is necessary to comprehensively evaluate the converter transformer system from the perspective of seismic resilience. A seismic resilience evaluation method of converter transformer isolation system is proposed in this paper. The state function of converter station related to the state of converter transformer system is established, and seismic resilience indicator and economic indicator are defined. Combined with the vulnerability curves of converter transformer, the calculation method of the indicators is proposed based on Monte-Carlo simulation. The converter transformer system in a typical ±800 kV converter station is taken as the research object, and different measures to improve its seismic performance such as adding spares or using isolation are considered to evaluate the seismic resilience of the system. The results show that this method can be adopted to quantitatively analyze the seismic resilience and economy of converter transformer system, and it is suitable for the evaluation of the seismic resilience of converter transformer and the optimization of improvement measures.