In order to study the low hygrothermal aging mechanism of Al/Zr/KClO₄ ignition agent， samples were aged at 85， 71， 60 ℃ and 50 ℃ . Thermal analysis， X-ray photoelectron spectroscopy （XPS） and scanning electron microscopy （SEM） X-ray spectroscopy （SEM-EDS） were used to analyze the thermal decomposition performance of Al/Zr/KClO₄ ignition agent and the changes of surface elements and morphology with temperature and time. The results show that some molecules on the surface of KClO₄ crystal are degraded to KClO₃ and KCl with the increase of aging time. The surface of Zr is further oxidized to ZrO₂ under the action of heat， and Al does not change significantly. Meanwhile， the surface morphology of each component did not change. The thermal decomposition activation energy and enthalpy of Al/Zr/KClO₄ ignition agent showed a decreasing trend with the increase of aging time. Compared with the unaged ignition agent， the activation energy decreased by 29.57 kJ·mol^-1 and the enthalpy decreased by 160 J·g^-1 after aging at 85 ℃ for 160 days. The aging mechanism function of ignition agent was obtained by fitting reaction rate， enthalpy value and surface element parameters of each component. It was found that the reaction rate， oxidation of Zr and degradation of KClO₄ could reflect the effect of time and temperature on low hygrothermal aging of ignition agent. The aging mechanism function was N-order reaction， the aging process is the oxidation of Zr and the degradation of KClO₄. The oxidation rate and reaction degree of Zr is greater than the degradation of KClO₄， and the aging activation energy was 95.86-128.90 kJ·mol^-1.