Abstract: Capability verification activities are any inter laboratory comparison or measurement review activities used to monitor the capability of laboratories. At present, competence verification program activities are widely used in calibration laboratories. According to CNAS-Cl03:2010 Accreditation Criteria for Proficiency Testing Providers, CNASRl02:2010 Rules for Proficiency Testing and other relevant documents, the scheme for capability verification of voltage transformers is formulated. The implementation process and improvement suggestions are given, which provides a certain reference value for the design of voltage transformer capacity verification plan.