Abstract: This paper analyze and Discuss the problem of the current standard “Method for Evaluating The Washability of Coal” in practical application. By calculating and demonstration the mismatch range of different separation density corresponding, put forward a dynamic correction method of ±0.1content under different theoretical separation density, achieve a dynamic evaluation method which fit different kind of coal., and overcome the “distortion” phenomenon of the current evaluating method. Recommendations to optimize current evaluating method, meet the general applicability of washability evaluating of various coal.