The invention relates to a common control circuit used for driving a plurality of loads. A switch circuit (10) comprises a plurality of transistors connected on the primary winding (12a) of a transformer (12); according the on/off of each transistor, input voltage Vin and grounding voltage are alternately applied on the primary winding (12a). A plurality of capacitors (C1a-C1d) are arranged for each of a plurality of fluorescent lamps (210), one end of the capacitor is commonly connected to a secondary winding (12b) of the transformer (12) and the other end is respectively connected to the fluorescent lamps (210). A control circuit (20) monitors current flowing through a specified current path (18) and carries out the feedback of the on/off state of a plurality of transistors of the control switch circuit (10) in the current path of the whole circuit comprising an inverter (100) and the fluorescent lamps (210), thus leading the monitored current to keep a specified state and adjustingthe switch power supply to the primary winding (12a) of the transformer (12).