The invention discloses a transformer with a grade-insulation structure, and the transformer comprise a low-voltage coil, a high-voltage coil, a shielding electrode, a grade-insulation structure and an iron core, wherein the low-voltage coil and the high-voltage coil are respectively arranged at the inner side and outer side of the grade-insulation structure, the iron core arranged at the inner side of the low-voltage coil is provided with a radiating folding screen, and a shield is arranged at the outlet electrode of the high-voltage coil to form the shielding electrode; and the grade-insulation structure comprises a first insulation layer, a second insulation layer, a third insulation layer, an angle ring, a fourth insulation layer, a fifth insulation layer and a sixth insulation layer which are arranged from inside to outside, and the angle ring stretches out of the low-voltage coil and the high-voltage coil. The transformer with the grade-insulation structure has the advantages that the material cost and energy consumption of the transformer are greatly reduced, the reliability of the product is improved, and the service life is prolonged.