Laomukong hydroelectric-station is an important node for cascade connection of the Minjiang channel. The natural reach between the dam site and the tail of the Qianwei hydroelectric-station will be upgraded to grade Ⅲ channel through regulation measures at the same time as the construction of the station. In order to protect ecological and human environment，the planned normal water storage level of Laomukong is required to reduce by 1 m. Combining with channel regulation，we research the regulation measures that take into account compensation for the water head of the station and the navigation conditions by reducing the water surface slope of downstream reach of the dam. We apply the mathematical model to compare and select the schemes，adjust the flow direction and gradually optimize the diversion ratio，and propose the best recommendation scheme. The results show that the optimization scheme 3 can ensure that the flow conditions at the connection segment of the approach channel satisfy the requirements of specification，also reduce the downstream water level and compensate the power generation benefits.