3D fluorescence super-resolution imaging technology can reconstruct the 3D structure of biological cells in space, which is crucial for observing the intricate internal structures of cells and studying the organization and function of tissues and organs. However, even with super-resolution imaging techniques that surpass the diffraction limit, the axial resolution typically only reaches one-third to one-half of the lateral resolution. Achieving true axial or 3D super-resolution imaging of samples remains a significant challenge. In light of this, this review summarizes the research progress in axial super-resolution imaging techniques, with a focus on the principles, developments, and characteristics of these techniques, and provides an outlook on their future development directions. This paper aims to provide valuable reference material for researchers in the field.