The diffraction limit of traditional optical device greatly restricts the further development of optical super-resolution systems. It is a great challenge to overcome the diffraction limit at a device level, and achieve label-free far-field super-resolution imaging. Optical super-oscillation provides a new way to realize super-resolution since it allows the generation of arbitrary small structures in optical fields in the absence of evanescent waves. The researches of optical super-oscillation and super-oscillatory optical devices have grown rapidly in recent decades. have been demonstrated theoretically and experimentally to show great potential applications in label-free far-field optical microscopy, far-field imaging and high-density data storage. In this paper, we gives a broad review of recent development in optical super-oscillation and super-oscillatory optical devices, including basic concepts, design tools and methods, testing techniques for super-oscillatory optical field, and their applications.