Through the experimentation of the noncrystalline alloy transformer , theoretical analysis and calculation of its finite element model ,and analyzing and exploring the vibration and noise source of the transformer, we choose the signal of the transformer vibration and noise to experiment in different frequency, receive datas ,analyze them and finally draw a conclusion that the experimental way and theoretical way have the same result that the transformer noise is not from current noise ,but from the up clamp structure which accepts prompting vibration radiating noise . That conclusion has a factual instructive suggestion for reducing transformer noise further.