Abstract: In order to solve the problem of real-time calculation of electromagnetic transient response of line commutate converter based HVDC (LCC-HVDC) system with high accuracy under large disturbance, the modeling method of LCC-HVDC transmission system was discussed in detail based on dynamic phasor method. Aiming at the requirement of calculation accuracy and complexity in engineering field, with the common commutation failure phenomenon at the inverter side under consideration, an easy-to-expand simulation model calculation framework was reconstructed. Multi-scene simulation experiments indicated that compared with the traditional dynamic phasor simulation scheme, the proposed framework can accurately reflect the transient response characteristics of the LCC-HVDC system under large disturbance of the AC system at the inverter side, while improving the calculation speed, and realizing the real-time calculation of the transient response of the LCC-HVDC system with high accuracy.