Abstract: With the continuous improvement of the power market trading system, the trading mode has become more diversified, presenting a hybrid trading mode in which bilateral trading and pool trading coexist. For bilateral trading models, especially green bilateral trading, the apportionment method of "proportional sharing" fails to satisfy the "bilateral" characteristics, and the low-carbon benefits of clean energy plants cannot be accurately distributed to the users they have entered into a bilateral transaction with. This paper analyzes the characteristics of carbon emission flows under different electricity trading modes and establishes a carbon emission accounting method that simultaneously considers a mix of bilateral and pool trading. First, according to the working principle of source-side coal-fired and gas-fired generating units, its dynamic carbon emission factor model is established based on the Informer model, which is a method with efficiency exceeding that of Transformer. Then, based on the power current, the bilateral transaction is modeled as a source-load inter-maximum carbon flow traceability problem, and based on the theory of the maximum flow, the accounting and apportionment of the carbon flow rate that takes into account the transmission losses are realized. After that, for the hybrid transaction mode that includes bilateral and interconnected transactions, the user carbon flow rate accounting method and the network loss carbon flow rate apportionment method are proposed to realize the carbon emission accounting of the whole link of the power system. Finally, the IEEE14 node system example is used to prove that the accounting method proposed in this paper is reasonable and fair for the mixed trading mode of bilateral and joint trading considering transmission loss.