The invention discloses a secondary voltage control method of a hybrid multi-infeed direct current system. The method comprises the steps of selecting a central point bus set participating in secondary voltage control, obtaining a sensitivity matrix of central point bus voltage to reactive power according to a power flow equation of a whole network, establishing a secondary voltage control model according to the sensitivity matrix, solving the secondary voltage control model to obtain reactive regulation quantity of controlled synchronous generators, high-voltage direct current convertor stations and other central points, and performing the secondary voltage control according to the reactive regulation quantity. The method can realize on-line coordination control of secondary voltage of the hybrid multi-infeed direct current system.