Abstract:Aiming at the application background of fault diagnosis of hydraulic system in automobile crane, a prototype of a fault diagnosis expert system of hydraulic system based on binary fault tree and casebased reasoning was researched and developed. In order to overcome the defects of traditional fault tree, to optimize the weights of the key properties of cases and to make more beneficial to the representation and processing of knowledge, optimal binary tree technology, genetic algorithm and database technology were used by this system. The accurate rate and efficiency of fault diagnosis were increased effectively, and the scalability and openness of expert system were improved. Experiment result proves the reasonability of the design shceme and the validity of the implementation method.