The effect of pH value on the kinds and number of Glucomannan hydrogen bonds was studied by experiments and molecular dynamics simulation, and that of the pH change on property and hydrogen bond was also analyzed. Ultimately, the impact of hydrogen bond change on its structure and property was discussed. The results of experiment and simulation were consistent with each other. In experiment, when pH > 7, peak strength of 1720 cm-1 v-acetyl is reduced and peak of V-OH is widened; and in simulation, the function of hydrogen bond of KGM increases, the number of hydrogen bonds increases by 19 and two kinds of hydrogen bonds are formed. Potential energy reduces by 443.1 kJ/mol. Acetylate is an important group to affect the gel intensity which can be improved by the hydrogen bond interaction. The effect of pH value on the kinds and number of Glucomannan hydrogen bonds was studied by experiments and molecular dynamics simulation, and that of the pH change on property and hydrogen bond was also analyzed. Ultimately, the impact of hydrogen bond change on its structure and The results of experiment and simulation were consistent with each other. In experiment, when pH> 7, peak strength of 1720 cm-1 v-acetyl is reduced and peak of V-OH is widened; and in simulation, the function of hydrogen bond of KGM increases, the number of hydrogen bonds increases by 19 and two kinds of hydrogen bonds are formed. Potential energy reduces reduces by 443.1 kJ / mol. Acetylate is an important group to affect the gel intensity which can be improved by the hydrogen bond interaction.