1. A television backlight driving device connecting to an LED lightstrip, the television backlight driving device comprising: an AC-DC module and an LED driving module; whereinwhen a power is on, the AC-DC module transforms an input supplied AC power into a DC voltage before supplying to the backlight LED lightstrip, when the LED driving module determines a detection current larger than a preset current but smaller than a first threshold, a constant-current output for a LED current is controlled by adjusting a duty ratio; when the detection current is larger than the first threshold or smaller than the preset current, the LED driving module feeds back the detection current to the AC-DC module; the AC-DC module then controls the value of the DC voltage according to the detection current; wherein
the AC-DC module comprises a main control circuit, a transform circuit, an output circuit and a second feedback circuit;
the main control circuit transmits the input supplied AC power to the transform circuit for a voltage transformation, the second feedback circuit regulates the transformed voltage before filtering and outputting a DC voltage by the output circuit to the backlight LED lightstrip for power supply; and
the second feedback circuit generates a corresponding control signal to the main control circuit according to the detection current feedback from the LED driving module, the main control circuit then adjusts the DC voltage according to the control signal.