In order to improve mechanical property of nitroamine propellant containing a large amount of high-energy solid filler,a certain amount of thermoplastic elastomer (TPE) was added. Through low-temperature drop weight test,charpy impact test for impact-resistance measuring and the closed-bomb test,the mechanical property and static combustion performance of nitroamine propellant containing the thermoplastic elastomer were studied. Results show that thermoplastic elastomer is able to effectively improve low-temperature tenacity and impact-resistance strength of the nitroamine propellant,and burning rate of the nitroamine propellant can be decreased by about 10%,burning rate pressure exponent of the nitroamine propellant can be reduced by about 2%.