Abstract: According to the problems of large treating capacity,the raw coal type complex and coal slurry difficult to treat existed in Buertai coal preparation plant,analyzed the size consist,surface potential, surface functional group and mineral composition of raw coal with the instrument of laser particle size analyzer,micro-electrophoresis apparatus,infrared spectrometer and X diffraction analyzer,to provide the early warning and timely and accurately direction for production,which measures guaranteed the continuously and safety operation of oversize coal preparation plant,greatly improved the production efficiency and economic benefit of enterprise.