High-precision ultraviolet lithography overlay register mark and overlay method

The invention belongs to the technical field of wireless optical communication, and particularly relates to an ultraviolet lithography overlay register mark and an overlay method. The ultraviolet lithography overlay register mark comprises three parts, namely a hollow square frame in the middle of the register mark and a cross part in the middle of the square frame, which are used for coarse alignment; the number parts, corresponding to the four vertexes of the hollow square frame, in the register mark are used for marking sub-version serial numbers needing to be overlaid; four graduated scales corresponding to the outer sides of the four edges of the hollow square frame in the register mark are used for fine alignment; the four graduated scales of the master plate are main scales, and the four graduated scales of the sub plate are sub scales. According to the invention, the overlay precision of the ultraviolet lithography is greatly improved while the definition of the ultraviolet lithography pattern is impr