The development direction of advanced solid-state lasers is higher output power and better beam quality. Rare earth ion doped yttrium aluminum garnet transparent ceramics are preferred materials for solid-state laser gain media, but thermal effects during the pumping process deteriorate the beam quality and hinder further increase in output power. The heat generation and dissipation of laser ceramics with complex configurations are more uniform during the pumping process, which can significantly reduce thermal effects. Compared with traditional preparation methods, 3D printing is able to form more complex design structures, suppress thermal effects, and achieve integration and miniaturisation of multi-module devices, driving lasers towards a wider range of applications. In this paper, several traditional methods for the preparation of laser ceramics with complex configurations are introduced firstly, and the advantages and limitations are analyzed. Then, the research status and problems in 3D printing yttrium aluminum garnet-based laser ceramics are systematically reviewed. Common 3D printing methods include direct ink writing, stereolithography, digital light processing, material jet printing, two-photon polymerization and micro-continuous liquid interface printing. Among them, there are interlayer defects in the samples printed by stereolithography and digital light processing, resulting in severe scattering losses. Material jetting printing combined with dry pressing can be used to manufacture planar waveguides. Two-photon polymerization and micro-continuous liquid interface printing are suitable for the fabrication of highly complex structures at micrometer scales. Direct ink writing not only enables the fabrication of laser ceramics for the first time, but also has the most extensive relevant research and is still the most promising method for the preparation of laser ceramics with complex configuration. At the end of this paper, the current problems and research prospects of yttrium aluminum garnet-based laser ceramics prepared by 3D printing are summarized.