The invention discloses a reactive compensation device which is connected with a mains supply and a load. The reactive compensation device comprises a comprehensive controller, a chopping control module and a capacitor bank control circuit, the chopping control module and the capacitor bank control circuit are respectively connected with the comprehensive controller, the capacitor bank control circuit comprises a multiple-pole switch and a plurality of series branches, the multiple-pole switch is connected with the mains supply, the series branches are in series connection with the multiple-pole switch, each series branch comprises a protecting resistor bank, a power factor controller connecting contactor combination, a reactor group and a reactive compensating capacitor bank which are in sequential series connection, and the comprehensive controller is used for continuously adjusting voltage on compensating capacitors by controlling the chopping control module and power factor controllers, so that continuous capacitive reactive adjustment is achieved. The reactive compensation device has the advantages of avoidance of low-order harmonics, simplicity in control and easiness in implementation.