The utility model discloses a potential transformer, the insulation layers of the primary winding of the potential transformer are distributed in cycle from inside to outside by taking every 3 layers as a group, the first layer of every insulation layer adopts 8 layers of polyester films and both the second and the third layers adopt 7 layers of polyester films, and the first, the second and the third layers are wound together; the number of turns of the enameled wires of every coil layer varies synchronously with the number of layers of the insulation layers, and the coil layers are distributed in cycle by taking every 4 layers as a group. By the adoption of the technical scheme, the utility model can reduce the errors of the signal detection of the potential transformer by means of the novel winding method, and can meet the requirements of the insulation between layers and the creepage distance under the premise that the error value meets requirement.