Abstract: To address the insufficient consideration on water level safety requirements at flood control stations in conventional reservoir flood control operation, this study proposes an optimal flood control operation method for reservoir group coupled with water level calculation at basin flood control stations. First, the station water level characteristics are analyzed through the multi-site water level and flow relationship to identify the key factors affecting the water level. The input features for water level calculation are screened according to the correlation between the influencing factors and the water level. The multi-layer feed-forward back propagation neural network（BP neural network） is introduced to fit the complex non-linear relationship between the input features and the observed water level, to realize the accurate calculation of water level at the station. Then, the safety margin index is proposed to quantify the station water level safety. With the objective of maximizing the overall safety margin of the downstream flood control stations, the optimal flood control operation model for cascade reservoirs, coupled with BP neural network, is constructed. Finally, a hybrid optimization algorithm（DPSA-POA-PSO） is developed to solve the model by combining the advantages of the Dynamic Programming Successive Approximation（DPSA）, Progressive Optimization Algorithm（POA） and Particle Swarm Optimization（PSO）. The results show that the water level calculation accuracy of the BP neural network is significantly improved by considering the station water level characteristics, and the flood level fitting deviation for typical floods is limited within 0.05m. Compared with the DPSA and PSO algorithms, the downstream overall safety margin from the hybrid optimization algorithm is improved by 0.88% and 2.58% in the joint operation of three cascade reservoirs, and is improved by 0.85% and 1.87% in the joint operation of five cascade reservoirs. Meanwhile, the derived operation schemes satisfies all the guaranteed water level requirements, which provides reliable support for improving the basin flood control safety.