Laser propulsion, laser energy transfer, and other major research directions have proposed a major demand for high brightness solid-state laser technology, making relevant research remain the focus of international attention. This paper presents the macro demand for high brightness solid-state laser technology and summarizes the current situation of technology research in China and abroad, its development trend, and the problems for further development. Based on this, the key technologies of high brightness solid-state lasers are analyzed, and some suggestions are proposed for future development. The slab laser and fiber laser have become the focus of research owing to their outstanding advantages. While the output power of a single laser is constantly improving, the laser output with high brightness can be realized using the beam combination method. Key technologies should be promoted to form a technical system as soon as possible, such as new laser materials, high-ranking semiconductor laser pump source, high precision packaging process, adaptive beam control, and key components for beam combination. It is proposed to establish research projects for the solid state laser technology that is represented by the surface gain slab laser technology and has a good potential for development. The research and accumulation of common basic technologies should be strengthened to lay a solid foundation for the continuous improvement of output brightness, conversion efficiency, and power mass radio of solid-state laser in the future.