The present invention provides a battery array voltage equalization device comprising: a sampling unit which samples the battery voltage signals of the battery array according to a sampling control signal; an analog-to-digital converting unit which converts the sampled voltage signals into a digital voltage signal; a control unit which generates the sampling control signal and a driving signal based on the digital voltage signal; an equalization unit which equalizes the voltage signals of the battery array based on the driving signal; a filter unit which is connected to the equalization unit and the battery array. The present invention applies the filter unit to filter out the ripple signal generated during equalization.