ABSTRACT This paper presents a comprehensive analysis of the effects of water content and ambient temperature on the mechanical stimulation threshold of hydroxylammonium nitrate (HAN) based liquid propellant. Based on the stability analysis of slow cook-off test for HAN-based liquid propellant, the mechanical sensitivity of the liquid propellant with different water content was evaluated at different ambient temperatures in detailed. Differential scanning calorimetry was employed to investigate the influence of water content on the stability, demonstrating a significant dependence on water content. Additionally, the impact sensitivity of liquid propellant, which is strongly influenced by the variation of initiating bond length with the ambient temperature, was investigated using large scale atomic/molecular massively parallel simulator (LAMMPS), highlighting a notable correlation between the impact sensitivity and ambient temperature. The findings of this research contribute towards understanding the hazard level associated with HAN-based liquid propellant, providing crucial guidance for its formulation design, practical application and safety management.