The invention relates to the technical field of transformers, in particular to a transformer body of an isolation transformer. The transformer body is arranged on an iron core, the transformer body comprises a capacitive screen sleeve, a high-voltage coil, a shielding electrode and insulating paper, the capacitive screen sleeve is connected with the shielding electrode, the high-voltage coil is arranged in the shielding electrode, the insulating paper wraps the outer side of the capacitive screen sleeve and the outer side of the shielding electrode, a low-voltage coil is wound on the iron core, and the low-voltage coil is arranged on the outer side of the insulating paper. According to the transformer body of the isolation transformer, the high-voltage coil is distributed on the outer sideof the inner low-voltage coil, the high-voltage coil and the low-voltage coil are separated by the shielding electrode, and the capacities of main insulation tolerance, electric field uniformizing and interference signal shielding are better achieved; moreover, the transformer body is small in size and good in heat dissipation performance, and in order to facilitate transportation of the transformer, the iron core in an oil tank can be mounted by using a horizontal structure.