Temperature and humidity are the important factors that affect the life span and service quality of missile. At present, most of the temperature and humidity monitoring methods that general used in army are in low measurement accuracy, fussy operation and difficulty to maintenance. So, in this paper, a low power, short distance wireless temperature and humidity monitoring system is designed. In this system, the SCM AT89S52 is used as the core, the AM2301 is used as the sensor which is a digital temperature and humidity integrated sensor, the NRF24L01 is used to realize wireless transmission, the LCD12864 is used to display and the keyboard is used to set temperature and humidity alarm threshold. The structure of the system is simple and the measurement accuracy is high, solved the problems of the existing system.