To explore the feasibility of organic acid removal of organic sulfur from high sulfur coal, three organic acids, oxalic acid, citric acid and ascorbic acid, were selected as desulfurization reagents. Combined with microwave irradiation technology, desulfurization experiments of high-sulfur coal treated with nitric acid were conducted. The orthogonal experimental results showed that microwave synergistic citric acid desulfurization had a better desulfurization effect. The removal rate of organic sulfur was 55.47% when the operation conditions of the reaction were 1 mol/L, 90 ℃ and 1000 W for 7 min. The desulfurization efficiency of oxalic acid and ascorbic acid was not good, and the removal efficiencies of organic sulfur were 32.35% and 21.37%, respectively. Fourier transform infrared spectroscopy showed that sulfones and sulfoxides were partially reduced and that the removal effect of thiophene was poor. X-ray photoelectron spectroscopy showed that the mercapto group in the mercaptan combined with hydrogen ions and escaped in the form of H2S. The content of aromatic thioether and aromatic thiol in the coal treated with microwave irradiation was only 0.1%. Research indicates that microwave-assisted organic acid removal of organic sulfur is feasible, and researchers can explore more efficient organic acids as desulfurization reagents based on this study.