Abstract: Reasonably allocating carbon emission obligations and enhancing the incentive scope of apportionment results while ensuring fairness are crucial for promoting the low-carbon development of power systems. For multiple carbon emission obligations, a two-way apportionment factor is constructed based on the carbon flow tracking model. This model accounts for load-following characteristics and incorporates unit carbon emission rating coefficients. The approach allows for the two-way apportionment of predicted carbon emissions from thermal power and load. The Shapley value method is then used to determine the quantitative carbon emission obligations for new energy units based on the marginal carbon emission contribution corresponding to output deviations. The results show that compared with results of the fixed factor method, the allocation method considering multiple related factors objectively reflects the real situation of individuals, clarifies the difference of carbon emission contribution between thermal power and load, solves the problem of difficulty in accurately measuring the implicit carbon emission of new energy, which has certain practical value and reference significance.