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. <EOS>