A new method, called the "thermal-shock method", was introduced for the production of highquality BaMgAl10O17:Eu (BAM) phosphor powder. A conventional solid-state process assisted by a thermal shock at 950 degrees C results in a pure BAM phase with no impurities such as BaAl2O4, MgAl2O4, or EuAlO3. When both AlF3 and H3BO3 are simultaneously used as the flux, this simple thermal-shock reaction yields the phosphor particles with highly improved morphology. Excellent emission intensity higher than that of commercial phosphor can be obtained after reduction at 1000 degrees C. Compared with other alternative liquid solution techniques, no use of any liquid medium that is harmful to the environment is one of advantages of the thermal-shock method for practical purposes. This synthetic process would be of great interest to the low-cost industrial production of high-performance BAM phosphor.