The present invention discloses a reactive compensation coordination control method during the DC emergency power support process and belongs to the technical field of power systems and automation. According to the technical scheme of the invention, according to a current running state and a to-be-lifted DC power, a reactive power, required to be consumed additionally for the DC system after the active power thereof is boosted, is estimated. Before the DC boosting process, filters or parallel capacitors of a corresponding number are put to use in the emergency manner. After the DC boosting process, reactive-load compensation equipment is put to use additionally according to the actual control manner of a convertor station. Meanwhile, the AC bus voltage of the convertor station is monitored. As a result, the condition that the AC voltage of the convertor station is out of limit due to the usage of the reactive-load compensation equipment can be avoided. The method can effectively improve the amount of the actual emergency power support in the DC large modulation mode. Meanwhile, the power imbalance problem of the power grid of a receiving end can be effectively relieved, and the safety and the stability of the power grid are improved.