Presently, the superintense and ultrafast laser technologies are developed towards all-solid-state, high-repetition-rate and new wavelength bands. As one of the most important factors, the development of new laser gain materials becomes more and more crucial. Rare-earth doped alkaline-earth fluoride laser crystals have high thermal conductivities and broad spectral bandwidths, which are very promising in generation of all-solid-state high-repetition-rate ultrafast lasers. In this work, the rare-earth cluster structure characteristics and the evolving processes and features are briefly summarized. Focusing on the structural design, spectral regulation and laser applications, the framework of local structure design for exploring new broadband ultrafast rare-earth doped alkaline-earth fluoride laser crystals is reviewed, along with the recent advances. The development trends were also prospected.