Data mining is an evolutionary process, and data and information are also manifestations of knowledge, but people see concepts, rules, patterns, laws and constraints more as knowledge. Based on data mining, an expert system works by reasoning using expert knowledge, and it consists of knowledge acquisition, knowledge base, reasoning machine, and interpretation part. The knowledge base is used to store experts' experience, knowledge and existing knowledge in the field, and whether it is perfect or not determines the performance of the expert system. Data mining is getting more and more attention, while the existing expert systems or decision support systems still mainly rely on manual collection and manual input of required knowledge and information, which is not only time-consuming and expensive, but also lags behind the time when making time-sensitive decisions and reduces the quality of decision-making.