According to calculations, achieving clean energy electrification will reduce global carbon emissions by 73.2%. The power industry plays a crucial role in CO₂ emissions reduction, making it essential to guide zero-carbon electricity consumption on the consumer side to support the achievement of the carbon peaking and carbon neutrality goals. Green electricity consumption calculation is a key technical requirement for zero-carbon electricity user certification, yet the current electricity market lacks relevant calculation methods. To address this issue, related research is conducted on the calculation method and market mechanism of green electricity consumption by zero carbon electricity users in the market environment. Firstly, based on an improved power transmission distribution factor power flow tracing method, a multi-level power flow tracing model is constructed, enabling real-time, multi-level, and high-precision calculation of green electricity consumption for zero-carbon electricity users. On this basis, a calculating method and market mechanism for grid-sourced green electricity consumption by zero-carbon electricity users are proposed, which covers access indicators, green electricity consumption calculation methods, and settlement mechanisms in line with existing electricity market rules. Finally, the proposed model is validated through a case study of a practical power grid in a southern city, demonstrating its effectiveness in providing efficient calculation methods and transaction mechanisms for cross-province, cross-regional, and neighboring grid-sourced green electricity users. Furthermore, the model guides zero-carbon electricity users to concentrate in distributed energy areas and shift loads to periods with higher system green power proportion, promoting the consumption of new energy.