The invention discloses a low-voltage control device applied to a low-voltage distribution network and aiming to keep the obvious effect of series compensation voltage regulation and the continuously adjustable output capacity of parallel compensation and to solve a low-voltage problem. The low-voltage control device comprises a series compensation module and a parallel compensation module which are connected in series with each other between a power supply and a load. The series compensation module comprises a series capacitor bank (C3) and a bypass circuit which are connected in parallel. The series capacitor bank (C3) comprises a plurality of series capacitors connected in parallel. The bypass circuit is a two-stage bypass circuit. The parallel compensation module comprises a plurality of parallel capacitors connected in parallel each of which is connected in series with a combination switch. One end of each parallel capacitor is grounded.