The invention relates to an orange long-
afterglow luminescent material and a preparation method thereof. The material takes Ca4Nb2O9 as a matrix and takes Pr<3+> as an activating agent, the expression formula of the material is [(Ca(1-x)Mx)(1-z)]4Nb2O9:(Pr(1-y)Ry)z, x is larger than or equal to 0 and smaller than or equal to 0.2, y is larger than or equal to 0 and smaller than or equal to 0.5, z is larger than 0 and smaller than or equal to 0.1, and M represents a Ca-site substitute element and is one or more of Mg, Sr and Ba; R represents a
rare earth or
transition metal element and is one or more of La, Nd, Sm, Eu, Gd, Yb, Lu, Cr and Mn; x, y and z represent
molar content. The material is synthesized in the air with a high-temperature
solid phase method. After excitation by
ultraviolet light or daily light, the material has a remarkable orange long-
afterglow characteristic, and people can watch
afterglow for more than 10 minutes with naked eyes in a dark place. The orange long-afterglow
luminescent material and the preparation method have the advantages as follows: (1) the preparation method is simple and easy to operate, and the
reducing atmosphere is not required; (2) the material has stable physicochemical properties, high brightness and long afterglow time; (3) the matrix elements of the material are all elements rich on the earth, no physical harm or environmental
pollution is caused during production and use of the material, and the material belongs to an environment-friendly material.