Structured light fields are a kind of special light fields that have tailored lightwave spatial structure. The generalized structured light fields are these kinds of fields including spatially variant amplitude, phase and polarization distribution as well as space array. Structured light fields have seen wide applications in optical manipulation, microscopy, imaging, metrology, sensing, nonlinear optics, astronomy, quantum science and optical communications owing to their distinct advantages. Structured light communication techniques include multiplexing communications and coding/decoding communications. In this review article, the recent progress of structured light coding/decoding communications is retrospected. Various generation methods of structured light fields and structured light coding/decoding communications with different spatial modes (orbital angular momentum mode, non-diffraction Bessel mode, linearly polarized mode, vector mode, space array), different coding methods (direct mode coding, high-speed mapping), and different scenarios (photonic chip, free space, fiber) are comprehensively reviewed. Future trend and perspective are also discussed. Structured light coding/decoding communications exploit the space domain dimensional resources of light fields, which provide a potential solution to address the new capacity crunch of optical communications and enable sustainable expansion of optical communications.