The allocation of carbon emission rights via auctioning has gradually become an irreplaceable part of the emissions trading system. However, the efficiency of allocations suffers due to low and volatile auction-clearing prices, which cannot account for price discovery. Furthermore, the fixed cap lacks flexibility in emission trading systems. Therefore, this study proposes a multi-round auction model with a floating cap for carbon allocation, integrating firms’ bidding strategies during the auction cycle and the impact of governmental regulations. The results show that (1) compared with static auctions, multi-round auctions can achieve a higher and more stable clearing price. (2) The mechanism provides flexibility for the distribution of profits and may encourage firms to participate in auctions. (3) Among all factors, the total supply of carbon emission permits and the economic environment more significantly influence the mechanism.

通过拍卖分配碳排放权已逐渐成为排放交易体系不可替代的一部分。但是，由于拍卖清算价格低且波动大，分配效率受到影响，这无法说明价格发现问题。此外，固定限额在排放交易系统中缺乏灵活性。因此，本研究提出了一个多轮拍卖模型，该模型具有浮动的碳分配上限，整合了拍卖周期中企业的竞标策略和政府法规的影响。结果表明：（1）与静态拍卖相比，多轮拍卖可以实现更高，更稳定的清算价格。（2）该机制为利润分配提供了灵活性，并可以鼓励企业参与拍卖。（3）在所有因素中，