A study of the effects of the pulp nature on desulphurization and de-ashing during high-sulfur coal flotation is described in this paper.Highlighted are the use of a solution oxygen gauge,a pH value gauge and a surface tension gauge to investigate changes in the pulp nature related to changes in the oxygen content,the pH value and the interfacial tension.The temperature before and after ultrasonic conditioning was also investigated.The results showed that ultrasonic conditioning resulted in a decrease in the oxygen content and the interfacial tension and an increase in the pH value and the temperature of the pulp.The perfect index of flotation and the perfect index of desulphurization of fine coal increased by 25.19% and 18.03%,respectively,after the pulp was ultrasonically conditioned.This study shows that ultrasonic conditioning can change the pulp nature and enhance the degree of desulphurization during high-sulfur coal flotation. A study of the effects of the pulp nature on desulphization and de-ashing during high-sulfur coal flotation is described in this paper. Highlighted are the use of a solution oxygen gauge, a pH value gauge and a surface tension gauge to investigate changes in the pulp nature related to changes in the oxygen content, the pH value and the interfacial tension. temperature before and after ultrasonic conditioning was also investigated. the results showed that ultrasonic conditioning resulted in a decrease in the oxygen content and the interfacial tension and an increase in the pH value and the temperature of the pulp. The perfect index of flotation and the perfect index of desulfurization of fine coal increased by 25.19% and 18.03% respectively respectively, after the pulp was ultrasonically conditioned.This study shows that ultrasonic conditioning can change the pulp nature and enhance the degree of desulphurization during high-sulfur coal flotation.