The invention discloses a UHV DC converter station dynamic reactive power optimization method in consideration of the coordination function of a phase modifier and a system filtering requirement. Themethod comprises main steps of: 1) establishing a UHV DC converter station dynamic reactive power optimization model M; and 2) by using a hybrid reactive algorithm of dynamic reactive power optimization, calculating the UHV DC converter station dynamic reactive power optimization model M to optimize the UHV DC converter station. According to a DC transmission power plan and a system dynamic reactive standby requirement, the method enables the remaining capacity of a phase modifier to participate in the steady-state reactive voltage adjustment of the converter station, and takes account that the phase modifier has high upper and lower adjustment margins, thereby realizing the coordinate of the phase modifier and the DC system to fully utilize the performance of the phase modifier.