Midlong term contract energy transaction is the main form of transaction in the early stage of new round electricity reform. Due to the uncertainty of wind power, midlong term contract energy decomposition faces enormous challenges. To solve this problem, a midlong term contract energy decomposition algorithm considering the uncertainty of wind power is proposed. An optimization model for a dayahead energy decomposition with minimum generation costs, power offsets, and carbon emissions is established and transformed into a singleobjective model through a normalized weighting method. Then the issue of the deviation between the actual energy generation and the planned energy is solved through an amendment algorithm. As the case study shows, the decomposition algorithm can achieve energysaving and emission reduction, and minimize the deviation of energy, while ensuring that the decomposition result is fair and feasible.