The present invention relates to an eyepiece optical system and device with a large field-of-view angle and high image quality, comprising a first lens group and a second lens group arranged successively along an optical axis from a human eye observing side to a micro display. The first lens group is composed of one or more lenses, and the second lens group comprises a Fresnel lens. The Fresnel lens comprises a Fresnel surface. By the use of a combination of a novel optical surface shape, i.e., the Fresnel surface shape, and traditional optical spherical and aspherical surface shapes, when focal lengths of various lenses and lens groups meet particular conditions, significant elimination of system aberration, reduction of the sensitivity of various optical components, and easy processing and assembly of the components can be achieved.