Abstract: A power drive system of light-emitting diode (LED) strings includes an isolation transformer, a current-sharing capacitor, two rectifying units, and a current control integrated circuit (IC). The isolation transformer has a primary-side winding and a secondary-side winding with a dotted terminal and a non-dotted terminal. The current-sharing capacitor is connected to the dotted terminal at one terminal thereof. One rectifying units is connected to the other terminal of the current-sharing capacitor, and the other rectifying unit is connected to the non-dotted terminal of the secondary-side winding. Each rectifying unit is connected to one LED string. The current control IC is connected between common points of the rectifying units and corresponding anode terminals of the LED strings and corresponding cathode terminals of the LED strings.