With the increase of number and capability of DC transmission lines feeding into East China power grid, the stability problem caused by commutation failure of multiple DC systems which resulted by AC faults has been more serious. By use of PSD-BPA transient stability simulation program, commutation failure of multiple HVDC of East China power grid in summer peak load operation mode in 2016 is simulated and analyzed. Simulation results show that commutation failure of eight DC transmission lines could be caused by three-phase short-circuit fault occurred in 500 kV lines in Shanghai area and nearby tie-lines; commutation failure of multiple DC lines impacts but not destroys the stability of the receiving-end system, and the influence degree is related with the equivalent commutation failure time; and inverter bus voltage during the recovery process of commutation failure can be affected by equivalent commutation failure time and load model. This work is supported by Science and Technology Project of State Grid Corporation of China "Study on Safety and Stability Control Technology for Extra High Voltage DC Successive Commutation Failure and Restart Condition