A cover and a lamp structure. The cover whose curvature has a light incident surface and a light outgoing surface, and includes a plurality of 3D micro-structures disposed thereon and arranged in the form of an array. When a light is emitted into the light outgoing surface from the light incident surface, the light emitting angle of the light outgoing surface is increased through the refraction of the 3D micro-structures, so that the occurrence of mura or spots due to uneven distribution of the light is avoid.