Abstract: To overcome the limitations of traditional manual measurements of transformer hexagon diagrams, such as low efficiency, high error rates, and poor result interpretability, this paper proposes an intelligent detection method based on phasor synthesis. The method acquires electrical quantities from all three sides of the transformer, applies a phase compensation algorithm to eliminate angular deviations caused by winding configurations, and utilizes a dual-branch power supply phasor synthesis technique to process current data under complex wiring scenarios. Additionally, it employs load ratio characteristics to enable intelligent identification of differential current. A dynamic visualization of the phasor synthesis process and electronic data management are also implemented through programming. Practical applications demonstrate that the proposed method significantly enhances the accuracy and efficiency of hexagon diagram measurements, standardizes field operation procedures, and offers a reliable technical foundation for verifying the correctness of transformer differential protection circuits.