Abstract: PX absorption and separation process is studied and analyzed using data mining methods based on SOM model,and the SOM model plays a key role in the whole data mining process.On the one hand,SOM model is used as an effective exploratory data analysis tool and provides evidence for further data mining.On the other hand,SOM algorithm provides directions in parameter selection and offer data support for other data mining algorithms(such as clustering,rule extraction,etc).In conclusion,two aims are obtained with the data mining algorithms: the optimized zone of operating parameters in different loads is obtained,and a realtime visualized evaluation model is built to improve the operation performances.