Abstract: In order to study the effect of soluble organic matter in coal on the particle size of coal dust, ethyl acetate was used as the extraction solvent. Fat coal was selected to produce five different particle sizes of coal samples and five different extraction times. The particle size distribution of the coal samples before and after extraction was experimentally studied using a laser particle size analyzer, and the Sauter mean diameter D_3,2 and dispersion σ_D were calculated to analyze and study the influence of soluble organic matter in coal on it. Research has shown that the longer the extraction time, the lower the content of soluble organic matter in coal, and the Sauter mean diameter D_3,2 of coal samples shows a non-linear decreasing trend; The change rate of D_3,2 in coal samples with a mesh size of 120-140 is the most significant, reaching 63.6% at an extraction time of 30 hours; The dispersion degree σ_D increases with the increase of extraction time, with a faster increase of 36.8% at extraction times of 12～18 h.