Abstract: With excellent mobility and environmental suitability of minitype rotorcraft, which is combined with traditional nuclear radiation detection equipments, a set of airborne radiation monitoring system was implemented by development of hardware and software, application of wireless communication, GPS and nuclear data processing technology. The terrain environmental impact on system can be ignored, and radiation damage to workers can also be avoided well. This paper introduces the configuration, operating principle and several key technical difficulties of the airborne radiation monitoring system, the design of key modules and measurement of dose rate response linear range are described comprehensively. The test result shows that the system can give a real-time and accurate detection on the radiation of environment, which can be used for daily environmental radiation monitoring or searching for lost or orphan gamma ray sources. A new method for nuclear accidents emergency is provided.