A verification device for transformer capacity tester is developed.Transformer capacity tester works are based on short-circuit impedance.This verification device uses a high power adjustable resistance to simulate the transformer short-circuit impedance with three-phase separation method,and with more accurate voltage and current measurement,calculates the transformer capacity from the simulation data,and gets the error comparing the value of transformer capacity tester.The article finally gives way to verify the device to complete the transformer capacity test traceability of value.