To explore the effect of environmental humidity on thermal decomposition kinetics of one newtype propellant,six kinds of saturation salting liquid such as CaCl₂·6H₂O,NaHS_O4,NaNO₂,NH₄Cl,KBr, and NaBrO₃ in the experiment were used, and conditions of different environmental humidities were achieved. From the different heating rate experiment (5,4,3,2 ℃/h) on this propellant by using microcalorimeter,some thermal data were obtained under the different relative humidity. According to the Ozawa and Kissinger method of calculating kinetics parameters,the apparent activation energy and frequency constant were obtained,and the results show that the reaction rate constant becomes bigger along with the increment of relative humidity.