The target of generation right transaction is to reduce carbon emission and pursuit the maximum of economic benefit. In the process of generation right transaction, the changes of genset active power output will affect system power flow, resulting in small load margin, high carbon emission, high network loss and a series of questions. In allusion to the problems, a generation transaction model, in which the preset emission reduction is taken as the constraint and under the premise of ensuring the secure operation and static voltage stability of power system the optimal network loss of power system is taken as the objective, is proposed. The proposed model is solved by constraint slack variable based centrality correction interior point algorithm, and the network loss and active power output would be translated as coal consumption to reflect the purpose of energy-saving emission reduction directly. The practicability and effectiveness of the proposed method are validated by simulation results of IEEE 30-bus system, IEEE 39-bus system, IEEE 57-bus system and IEEE 118-bus system. This work is supported by National Natural Science Foundation of China (No. 51367014).