Reservoir operation rules, as an important tool to guide reservoir operation, are not only the decision-making reference in the reservoir planning and design period, but also one of the key technologies affecting the comprehensive benefits of the reservoir in the operation and management period. Therefore, based on the historical operation data of reservoirs in the upper reaches of the Yangtze River, the number of periods, early water level, inflow, outflow and current inflow were selected as the influence factors to form the input factor set combined with the reservoir operation principle and operation characteristics. Comprehensively considering the characteristics of operation data and the principle of decision tree, the end of period water level was determined as the model output and then the corresponding simulated water level evaluation index was proposed based on the reservoir regulation capacity. The correlation coefficient and mutual information were used as the correlation evaluation index of model input factors, and the tree Parzen evaluator was introduced to optimize the number of input factors and algorithm super parameters. Finally, the reservoir operation rule extraction model based on decision tree and its integrated model was established and the reservoir operation rule integrating historical operation process and expert experience was formed. The experimental results show that the decision tree and its integrated model have strong ability and applicability in the extraction and application of reservoir operation rules.