BaMgAl10O17 :Mn2+ green phosphor was prepared by high temperature solid state reaction and the optimal chemical formula is Ba0.85 MgMn0.15 Al11.993 B0.007O19. The influences of milling and ultrasonic-dispersal on the luminescent properties, granularity and appearance of the phosphor were investigated, and the green phosphor with fine grain and uniform dispersion to be adapted to plasma display panels was obtained. A Hitachi F-4500 fluorescence spectrophotometer was used to measure the luminescent performance of the phosphor, and the vacuum ultra violet (VUV) fluorescence spectroradiometric system (Zhejiang University Sensing Instruments Co.,Ltd.) was used to measure the luminescent performance under 147 nm excitation. A scanning electron microscope (SEM) was used to identify the size and shape of the particles. X-ray diffraction (XRD) was used to confirm its crystalline structure.According to this study, the optimal after-treatment processes were as follows: milling time 5 min, milling medium 15 ％ C2H5OH, dispersal time 90 min and dispersal medium 15％ C2H5OH.