This paper researches on a generating scheduling model which is based on the supply function and aims to maximize the social surplus. It's divided into two situations to conduct a study. One studies the electricity transmission scheduling model without the consideration of transmission constraints and presents the model algorithm, and then we can get the unified clearing market prices, the electricity consumption of users and the electricity generating capacity. One considers the transmission constraints and presents the model algorithm, and then we can get all the different node electricity prices, the electricity consumption of users and the electricity generating capacity under transmission constrained circumstance. Finally, the paper gives a scheduling model example under power transmission constraints.