Abstract: Minitab has powerful functions of experimental design and data analysis,and it could be fast,accurate and reliable on orthogonal experiment design and data analysis,playing obvious role in promoting fast experiment design and accurate data analysis of multiple factors involved in actual coal preparation. Furthermore it will be of great significance to improve production efficiency and reduce cost. Taking test of coal ashing conditions for example,the application of Minitab in orthogonal test design and data analysis is described in detail.