Distortionless compact off-axis near-to-eye display optical system

The invention relates to the technical field of optical imaging, in particular to a distortionless compact off-axis near-to-eye display optical system which comprises a display, a first free-form surface element and a second free-form surface element, and a first sub-optical path and a second sub-optical path are formed through the first free-form surface element and the second free-form surface element; a first light inlet curved surface is arranged on one side of the top of the first free-form surface element, a light outlet curved surface is arranged below the light inlet curved surface, and a first reflection curved surface and a second reflection curved surface are sequentially arranged on the side, away from the first light inlet curved surface, of the first free-form surface element from top to bottom. One side of the second free-form surface element is provided with a fitting curved surface matched with the second reflection curved surface and a second light inlet curved surface far away from one side