The traditional cable data transmission is high cost and big interference. instead, the wireless data transmission has advantages like: low cost, better applicability and lower interference. So, a kind of handheld wireless temperature and humidity control system based on the msp430 microcontroller, CC1101 wireless transceiver module and DHT11 temperature and humidity sensor is designed. This system not only can receive data by hand-held device, but also can connect to computer with RS232 line. In this paper, software and hardware design ideas have been givn. The practice usage indicates that the system is stable, power consumption is small, and can be used in various occasions where the temperature and humidity data is needed.