Overview: Visible lasers are used extensively in laser color display, laser medical treatment, quantum information, optical communication, and other applications. Trivalent Pr-ion (Pr³⁺) has attracted much attention due to its rich transitions in the visible band. As early as the 1960s, praseodymium-doped (Pr³⁺) crystals were investigated as gain mediums for laser production. Compared with the way of obtaining visible laser by optical nonlinear processes such as frequency doubling and mixing, the way of directly down converting the laser energy level by using Pr³⁺ doped crystal to obtain visible laser avoids the use of the nonlinear optical crystal, which makes the laser have high conversion efficiency, compact structure, good quality of laser beam, and no requirement of strict temperature control. Especially in recent years, the emergence of commercial pump sources such as laser diode (LD) and optically pumped semiconductor laser (OPSL) has made great progress in the research of Pr³⁺ doped solid-state lasers. In this paper, Pr³⁺ solid-state lasers are divided into three types: continuous-wave output type, pulse output type and single longitudinal mode output type. Among them, the continuous-wave laser is typical in green, orange and red laser bands. The laser output power can exceed the watt level. The maximum output power at 522 nm green laser is more than 4 W, and the maximum power at 607 nm orange laser is 4.88 W. The maximum power at 639 nm red laser is up to 8.14 W. For pulse laser, the laser output with a pulse width of tens to hundreds of nanoseconds can be obtained in Q-switching, and the pulse width in mode-locking is narrower. The mode-locked pulse widths of 8 ps, 400 fs and 1.1 ps are obtained at red 639 nm, orange 613 nm and 604 nm respectively. The mode-locked pulse widths of other visible optical bands have been reported to range from more than ten picoseconds to hundreds of picoseconds. In the aspect of single longitudinal mode, the research work of realizing single-frequency laser output by using Pr³⁺ doped crystal mainly focuses on 360 nm UV, 604 nm, 607 nm orange laser and 639 nm, 640 nm red laser. At the same time, taking time as the mainline, this paper summarizes the research history and current status of Pr³⁺ doped solid-state lasers, and looks forward to the future of Pr³⁺ doped solid-state lasers.Visible lasers are used extensively in laser color display, laser medical treatment, quantum information, optical communication, and other applications. Trivalent Pr-ion (Pr³⁺) has attracted much attention because of its rich transitions in the visible band. Especially in recent years, the emergence of commercial pump sources such as laser diode (LD) and optically pumped semiconductor laser (OPSL) has made great progress in the research of Pr³⁺ doped solid-state lasers. According to the three output types of Pr³⁺ doped solid-state lasers: continuous-wave output, pulse output and single longitudinal mode output, this paper introduces the typical work of each output type in a specific band. The research history and current status of Pr³⁺ doped solid-state lasers are summarized with time as the main line, and the future prospects of Pr³⁺ doped solid-state lasers are projected.