In hybrid electricity markets, the coupling of transactions complicates the tracing of carbon emission paths between sources and loads, while the mechanism for allocating carbon responsibilities associated with network losses remains unclear. These challenges hinder the realization of accurate carbon accounting in new electricity system. To address this challenge and align with low-carbon-oriented carbon management objectives, a framework and methodology for carbon emission path tracing and bidirectional allocation of network losses is proposed, integrating directed graph modeling with path optimization. A virtual lossless network is constructed to decouple bilateral trading from pool trading. For the single-source-single-sink structure of bilateral trading, a low-carbon path priority maximum flow model is developed by introducing a carbon emission factor-based prioritization mechanism. For the multi-source-multi-sink structure of pool trading, a “BFS ordering followed by DFS tracing” mechanism is designed to achieve bidirectional allocation, thereby a recursive sequence for virtual node carbon flow distribution is established. Case studies demonstrate that the proposed framework significantly enhances the accuracy and fairness of carbon emission tracing in hybrid markets, highlights the value of low-carbon-oriented path tracing, and provides technical support for the development of low-carbon power systems under the “dual-carbon” goals.