Based on weather facts and synoptic cause of formation, a strong dust devil weather case occurred on 18th to 19th April, 1998 is analyzed and diagnosed, and then numerical simulation with nonhydrostatic MM5 model for this case is made. The result shows that cold air from the western Siberian moves rapidly eastward and forms strong frontal zone over the western Xinjiang, which corresponding surface cold front moves to such special underlying surface as desert, gobi in Xinjiang, Inner Mongolia, Gansu and Ningxia provinces where were heated, and as a result, gale, strong dust devil weather would form. The MM5 model can successfully simulate the formation and development of this surface severe gale and upper air front zone.