An electrical isolation apparatus for a photovoltaic power generating system, wherein the electrical isolation apparatus comprises: a primary stage, configured to connect to a first signal device, wherein the primary stage comprises a first reference circuit and a first signal transmission circuit; and a secondary stage, configured to connect to a second signal device, wherein the secondary stage comprises a second signal transmission circuit and a second reference circuit, wherein the first reference circuit, the first signal transmission circuit, the second signal transmission circuit, and the second reference circuit are not in contact with each other, and are sequentially disposed in parallel to a first plane, and there is a spacing between a projection of the first reference circuit on the first plane and a projection of the second reference circuit on the first plane; there is a spacing between a projection of the first signal transmission circuit on the first plane and a projection of the second signal transmission circuit on the first plane; the first signal transmission circuit comprises a first part and a second part; wherein a projection of the first part on the first plane overlaps with a projection of a first region of the first reference circuit on the first plane, and a projection of the second part on the first plane overlaps with a projection of a second region of the second reference circuit on the first plane; and the second signal transmission circuit comprises a third part and a fourth part; wherein a projection of the third part on the first plane overlaps with a projection of a third region of the second reference circuit on the first plane, and a projection of the fourth part on the first plane overlaps with a projection of a fourth region of the first reference circuit on the first plane. a primary stage, configured to connect to a first signal device, wherein the primary stage comprises a first reference circuit and a first signal transmission circuit; and a secondary stage, configured to connect to a second signal device, wherein the secondary stage comprises a second signal transmission circuit and a second reference circuit, wherein the first reference circuit, the first signal transmission circuit, the second signal transmission circuit, and the second reference circuit are not in contact with each other, and are sequentially disposed in parallel to a first plane, and there is a spacing between a projection of the first reference circuit on the first plane and a projection of the second reference circuit on the first plane; there is a spacing between a projection of the first signal transmission circuit on the first plane and a projection of the second signal transmission circuit on the first plane; the first signal transmission circuit comprises a first part and a second part; wherein a projection of the first part on the first plane overlaps with a projection of a first region of the first reference circuit on the first plane, and a projection of the second part on the first plane overlaps with a projection of a second region of the second reference circuit on the first plane; and the second signal transmission circuit comprises a third part and a fourth part; wherein a projection of the third part on the first plane overlaps with a projection of a third region of the second reference circuit on the first plane, and a projection of the fourth part on the first plane overlaps with a projection of a fourth region of the first reference circuit on the first plane.