The market-oriented trading of distributed energy with the participation of multiple prosumers has gradually become a solution to promote the consumption of distributed energy. The transaction preferences of prosumers have a significant impact on market transaction efficiency. How to design a market transaction mechanism that considers the transaction preferences of prosumers to promote efficiency improvement has become a current research hotspot. In this paper: firstly, a regional electricity market trading framework with the participation of multiple prosumers at the distribution network level was established; Secondly, the internal resources of prosumers were analyzed, and the mathematical models of their output units and loads were constructed; Thirdly, a peer-to-peer (P2P) transaction mechanism for regional electricity market was designed based on the combinatorial double auction theory, which takes into account different energy demands and low-carbon preferences of prosumers, among them, with the goal of minimizing operating costs during the scheduling cycle of prosumers, the internal resources were coordinated to achieve balance and their energy supply - demand plans were obtained (as their bidding electricity quantity), and on the basis of considering the low-carbon preferences, a Supply Function Equilibrium (SFE) model was adopted to construct their bidding price strategy (as their bidding electricity price). Third party auctioneer was used to coordinate P2P transactions between prosumers, and different bidding types were introduced to accurately express prosumers´ different energy demands during the trading process. Finally, the effectiveness and feasibility of the proposed P2P transaction mechanism were verified through numerical examples.