With the function level of Lancang-Mekong River navigation increased, the competitive water use between navigation and power generating is more and more prominent. It is important to balance the water used for power generation and navigation to ensure the benefits of generating electricity and increase the reliability of navigation water use. This study builds a multi-objective optimization scheduling model, which takes the maximum benefits of generating electricity and navigable flow assurance as the objective function. Through long-term adjust calculation, the generating capacity, the benefits of generating electricity of cascade reservoirs, the discharge, and the reliability of the hydro-power station are analyzed, respectively. The results show that the total generating capacity of the six cascaded hydro-power stations is equal to the annual output of reservoirs set in the early planning stage. The time reliability of monthly output discharge for Jinghong hydro-power station above 1000 m3/s is 100%, which is higher than that of 2019 to 2022(45.8%). It demonstrates that the optimal operation of cascade reservoirs can significantly increase the discharge reliability in the period of 800～1000 m3/s without sacrificing the benefits of generating electricity; it can provide extremely favorable conditions to improve the navigation level below the Jinghong hydro-power station waterway.