In the context of the development of energy Internet

it has become an inevitable trend for distributed generation （DG）and electric heating load to achieve internal production and consumption by forming a power supply alliance

promote the consumption of new energy

and participate in market-oriented transactions. The conditions for the existence of the market transaction mode of power supply alliance composed of DG and electric heating load are given. Secondly

using the cooperative game theory

the pricing mechanism under the alliance transaction mode is established

and the calculation method of the interests of each participant is proposed. Then

with the goal of optimizing the interests of the sellers of the proxy power supply alliance

the model of power supply alliance selection

day ahead matching and quotation is constructed. Finally

through the simulation and analysis of the alliance transaction mode

the feasibility and the effectiveness of the optimization decision model are proved.