Abstract: The research on fault diagnosis technology is important to improve the reliability of wireless sensor network system. This paper reviews recent domestic and international fault diagnosis technology research on wireless sensor network system, including node-level hardware failure, software failure and network-level fault diagnosis techniques. And four major diagnostic techniques are made a comparison over the diagnostic speed. Finally, the sensor fault diagnosis technology trends and issues are to be made a certain analysis and discussion.

Key words: wireless sensor network, topology, homogeneous network, heterogeneous network