With the continuous deepening of the power market reform, the contradiction between the priority assurance electricity of the power generation side and the consumption side and the free competition market trading electricity is gradually prominent, which affects the power plan balance management and market organization design of market managers. Under this background, considering multiple kinds of constraints such as unit maintenance, electricity assurance, contracts execution, actual generation deviation, and taking maximizing the electricity guarantee at the generation side as the objective, this paper constructs a modified matrix factorization model based on the two-way horizontal-vertical intersection of power generation priority, and designs an engineering practical management mechanism that meets the two electricity balance management needs of annual balance and rolling balance, and verifies its effectiveness and adaptability by practical examples, which provide important support for market management and system stability in the power market development.