The 2025 35 kV voltage transformer metrology comparison project, led by the Standard Instrument Transformer Laboratory of the Electric Energy Measurement Supervision Center of the Inner Mongolia Electric Power Research Institute, completed full-region on-site transmission and testing over a two-month period. The comparison, covering 11 power supply units under the Inner Mongolia Electric Power Group, employed a "petal-shaped" dual-route transmission scheme. The goal was to establish a unified measurement value transmission system across the region and provide technical support for fair settlement of electricity trade. Final data processing and report generation will be completed in September.