Abstract: Power interaction occurs in the initialization process of different components in the electromagnetic transient simulation system of large-scale new energy connected to the power grid through HVDC based on voltage source converter (VSC-HVDC). This will lead to prolonged initialization time, increased difficulty, and deteriorated stationarity of waveform, which cannot meet the needs of subsequent electromagnetic transient fault simulation analysis. The article adopts the strategy for electromagnetic transient initialization based on power flow solutions, analyzes the interaction between different new energy equipment during the initialization process, and studies the initialization method of new energy stations based on clamp voltage sources. The initialization characteristics of VSC-HVDC under different control modes are revealed, and the initialization methods of multi-terminal VSC-HVDC considering different control modes are studied. To avoid power interaction during the initialization process between multiple converter stations, converter stations, and new energy stations, and improve initialization efficiency, an efficient initialization method for electromagnetic transient simulation systems of large-scale new energy connected to the power grid through VSC-HVDC is proposed. Finally, the full electromagnetic transient simulation systems under different scenarios are established in the PSD-PSModel full electromagnetic transient simulation software for initialization, verifying the rationality and effectiveness of the proposed initialization method.