The invention discloses a power circuit for a liquid crystal television. The power circuit is arranged between a backlight LED (light-emitting diode), a machine core and an external input power supply, and comprises a filtering and rectification circuit, a main topological circuit, a load voltage detection and feedback circuit, a PWM (pulse width modulation) control circuit and a step-down circuit, wherein external input power is divided into two paths after entering the main topological circuit, one path is input to the backlight LED, and the other path is input to the machine core through the step-down circuit; the load voltage detection and feedback circuit is connected with the backlight LED and the PWM control circuit respectively, and is used for detecting the voltage of the backlight LED, and feeding back the detected voltage to the PWM control circuit to regulate PWM output and further regulate voltage input into the backlight LED. Compared with the prior art, the power circuit has the advantages that the efficiency is greatly improved, the cost of a power device is remarkably lowered, and the power circuit has broad popularization and application prospect.