UHV three-terminal hybrid DC power distribution is flexible, compared with the conventional two-terminal DC power, the interaction between power regulation and AC system is complex. How to reasonably distribute the three-terminal DC power will directly affect the safe and stable operation of the integrated power grid. In order to solve this practical problem, taking the world’s first UHV three-terminal hybrid DC—±800 kV Kunliulong DC project under construction as an example, this paper analyzes the power distribution requirements in the normal DC operation, pole (valve group) fault and power emergency control scenarios in the first time, summarizes the basic principles of three-terminal UHVDC in combination with the actual operation of the China Southern Power Grid(CSG), and proposes the UHV three-terminal hybrid DC power distribution schemes in various typical scenarios. All the principles and schemes have realized the flexibility of UHV three-terminal hybrid DC power distribution, and can reduce the power loss of UHVDC as much as possible, improve the interaction between AC and DC, and promote the safety and stablity of the main network of the integrated power grid.