The invention provides a lutetium aluminate green fluorescent powder having a chemical general formula represented by Ce[x]Lu[3-x-y]M[y]Al[5]O[12], wherein M is at least one of La, Gd, Pr, Nd, Sm, Eu, Ga, Tb, Dy, Ho, Er, Tm, Yb and Sc, 0<x<0.1, and 0<y<0.1. The fluorescent powder is prepared by a high temperature solid phase method, and the synthesis temperature is 1300-1500 DEG C; the prepared fluorescent powder has the advantages of good optical properties, no impurity phases, good crystallization and basically no agglomeration, has nearly spherical particles and has the median particle size D50 adjustable in the range of 8-12 [mu]m; at the same time, the fluorescent powder has the advantages of relatively wide excitation spectra, high relative brightness, simple preparation process, low energy consumption, and environmental protection. The green fluorescent powder provided by the invention is suitable for preparation of white LED devices with combination of other primary-color fluorescent powders, and can be applied in the fields of illumination or display systems and the like.