The utility model provides an it is changeable than voltage transformer error detection device, should be by error measuring device, the standard voltage mutual -inductor TV0 that steps up certainly, examination article voltage transformer TVX, take the tapped line to wind the non inductive resistance and the relay constitutes. The standard voltage mutual -inductor of customization is adopted in the invention, has solved changeable problem than voltage transformer testing standards ware, adopt voltage transformer load error curve extrapolation and self -control to take the four -range wire -wound non inductive resistance of taking a percentage, adopt the ratio voltage method of substitution, solved mutual -inductor error detection device voltage range adaptability problem, utilize voltage transformer examination equipment such as current stepup transformer, mutual -inductor error detection device, can realize changeable detection than voltage transformer error. The utility model has the advantages of the device is succinct, economy, science, practicality, maneuverability are strong, with low costs.