The establishment of the bulk power grid platform is the foundation for achieving the optimization of generation resources. In the actual process of generation allocation plan, it tends to think of each cross-region transmission line separately. Given this background, first, a model for cross-region DC power consumption is built. Then, an index of fairness for maximum receiving electric power is put forward to evaluate the power consumption plan. The index consists of a cross-region DC generation allocation function with the goal of maximum receiving cross-region generation resources and a fairness for thermal power benefits function with the goal of minimizing the standard deviation of thermal power substitution capacity bias ratio variation for each province of receiving end. Finally, a method of determining generation allocation path based on the shortest path problem in graph theory is put forward, which is combined with the semi-definite programming (SDP) to determine the generation allocation plan. A practical example is employed to demonstrate the feasibility and efficiency of the developed model and method.