The invention discloses a three-level converter direct-current side neutral-point voltage balance control method based on SVPWM, and belongs to the technical field of electric system power electronics. According to the method, median vectors are eliminated, and small vectors and large vectors are combined to form a reference voltage vector. The method comprises the steps of analyzing the influence of an SVPWM control mechanism and the on-off state on the neutral-point potential, partition judgment is carried out on voltage space vectors, determining the action time of each space vector, and determining the vector sending sequence. By means of the method, change of the on-off state of a power device and loss of a converter are reduced, neither a voltage sharing circuit nor a hardware circuit is needed, and the dynamic balance performance of the direct-current side voltage of the three-level converter is improved. The control method is simple and has great reference value for engineering application.