Electron-phonon coupling effect is an important physical phenomenon for laser wavelength extension in solid-state laser materials. This review summarized the history of tunable solid-state lasers, namely, color-center, transition-metal, and rare-earth lasers, focusing on the spectral homogeneous broadening induced by the electron-phonon coupling effect. Recently, based on the multiphonon-coupling theory, an ultrabroadband laser emission far beyond the fluorescence spectrum was reported,thus greatly extending the available laser wavelengths. Moreover, various self-frequency doubling lasers were developed by combining the multiphonon-coupling and nonlinear-optical-conversion into one single crystal, thereby creating some low-cost and compact visible laser modules, covering the cyan-green-yellow-orange-red spectral range. These newly developed laser sources can meet the urgent demand of laser-based surgery and laser display applications, which can push and promote the rapid development of the all-solid-state laser technology.