Deep-ultraviolet (DUV) nonlinear optical (NLO) crystal is a key material for the solid-state lasers to generate DUV coherent lights. Due to the limit of band gap, NLO coefficient and birefringence, theexisting NLO crystals are difficult to generate DUV coherent lights by phase matching, except KBe2BO3F2 crystal. It’s a new idea to solve the phase matching problem of DUV NLO crystals based on the quasi-phase matching principle. A detailed description of properties of BaMgF4 crystal, Mg3B7O13Cl crystal and LaBGeO5 crystal, and their applications on the generation of DUV coherent lights based on the quasi-phase matching principle are introduced. Finally, the suggestion and prospect on DUV quasi-phase matching crystals are presented.