To explore the gel mechanism of hydroxylamine nitrate-based gel propellant， the molecular dynamics （MD） simulations were employed to investigate the microscopic behavior， final crosslinking configuration， and the hydrogen bonding distribution that influences the stability of the hydroxylammonium nitrate/polyacrylamide （PAM）/methanol/water propellant gel system of PAM molecules. Results show that PAM molecules primarily form interaction nodes through intermolecular hydrogen bonding interactions， further promoting the expansion of molecular chains and the construction of a three-dimensional network framework. As the mass fraction of PAM increases from 2.7% to 10.7%， the number of hydrogen bonds formed between PAM molecules increases from 11.98 to 109. Both Van der Waals force interactions and hydrogen bonding jointly drive a self-accelerating crosslinking process of PAM molecules. The radial distribution of hydroxylammonium groups and nitrate ions in hydroxylammonium nitrate shows a bimodal characteristic. The introduction of PAM weakens the intensity of the first peak， as it reduces local interaction and energy density by forming crosslinking "domains"， thereby enhancing the stability of the propellant.