Abstract: In order to further study the electrospinning technology and the controllable preparation of Janus micro/ nano fibers, Janus fibers materials with heterogeneous structure characteristics have been more widely used in the field of multi-functional materials. In recent years, with the continuous development of electrospinning technology, the spinning process of Janus fiber has gradually expanded from spinning device, spinning parameter optimization to improve fiber parallelism rate, and gradually developed to the guided design direction of fiber morphology diversification, structure multiphase and composition multiphase, in order to promote the rapid development of Janus fiber in the field of multi-functional materials. In this paper, the co-axial and coaxial-structure Janus micro/nano fibers prepared by electrospinning technology and other fiber structures derived from them are reviewed. The research progress and achievements in the preparation methods, formation mechanism and structural regulation of Janus fibers with different morphologies and structures are compared. It is further demonstrated that electrospinning technology has wide application potential in realizing micro- and nano-scale oriented structure control of Janus fibers.