With expanding applications scale of wireless sensor networks（ WSNs）

fault detection and diagnosis become the key technologies to guarantee normal operations

security and reliability of system in a variety of sensor network applications. Therefore

define three kinds of state for multi-sensor systems

based on fault detection information establish state transition matrix. Then sensor fault information can be predicted by Markov model

which provide decision-making basis for fault detection and diagnosis. In addition

expansion of packet information field includes fault type

node positioning

node metastasis to normal state after troubleshooting and diagnostic features and other information are stored in gateway or sink node

provide basis for improving diagnostic precision and efficiency of fault detection and system resources utilization. Experimental results show that compared with traditional algorithm

the proposed fault detection and diagnosis algorithm has higher fault detection precision

shorter fault diagnosis delay

accurate determination fault type and other properties.