Abstract: When ultra-high voltage DC transmission (UHVDC) transports high proportional clean energy, the over-voltage problem during a system fault is the key factor restricting the DC transmission capacity. Aiming at the shortcoming of the traditional PI current controller, this paper proposes a method of dynamic parameter control based on predicting the changing trend of the DC current. Combined with parameter optimization of voltage dependent current order limit function, the low-voltage and the over-voltage phenomena of the AC system at the sending end during commutation failure are obviously improved. After being verified by the real-time simulation and the on-site commissioning test, the research results have been applied to the UHVDC project of Qinghai to Henan provincial transmission project and several other transmission links. It effectively suppresses the AC overvoltage under a transient fault, improves the performance of the DC system during the fault recovery, and increases the transmission proportion of the new energy.