To clarify the electromagnetic, vibration, and loss characteristics of the internal components of a converter transformer under DC bias conditions and their influencing mechanisms, a series of studies are conducted using the finite element method and model experiments. This paper quantifies the influence of different DC contents on the magnetic flux density, force, and displacement distribution characteristics of the iron core and winding and analyzes the internal relationship between various indicators. The inflection point of the DC bias coefficient on the vibration is obtained and the contribution mechanism of the different responses of the iron core and winding to this inflection point is explained. The value of the DC bias coefficient for changing the main vibration frequency is determined. When the DC bias coefficient is 1.0 and 1.5, the main frequency of vibration moves to the right to 250 Hz and 350 Hz. Based on the principle of similarity, a DC bias vibration experimental platform for converter transformers is developed, and DC bias magnetic experiments are conducted to verify the reliability of the simulation results.