Abstract: In order to improve the correctness of fault diagnosis of gear pump,the normal cloud neutral network is applied in it．The normal cloud neutral network was established combining the normal cloud model and neural network,and the structure of normal cloud neutral network was constructed,and the corresponding algorithm of every la-yer was given.The structural identification was achieved based on cloud transfer,and the weight and threshold value was optimized through training．Finally,the simulation of fault diagnosis of gear pump based on normal cloud neutral network was carried out.The results show that normal cloud neutral network can obtain the fault diagnosis of gear pump correctly,and the efficiency of fault diagnosis is high.

Key words: Cloud neutral network,Gear pump,Fault diagnosis