This invention relates to a processing device and processing method of high dynamic contrast for liquid crystal display apparatus, the processing device comprises a receiver, an inverter, and a source driving IC connected with a central processing module. The processing method includes: performing a histogram statistical process on received low voltage Differential Signaling data; obtaining a backlight source dimming coefficient and a Gamma reference voltage parameter of the same frame of picture according to the result of the histogram statistical process. controlling the brightness of the backlight source according to said backlight source dimming coefficient; controlling the voltage of the pixel capacitor on the liquid crystal panel according to said Gamma reference voltage parameter. This invention respectively adjusts the brightness of the backlight source and the voltage of the pixel capacitor of the liquid crystal panel simultaneously, and hence the dynamic contrast of the picture is increased, the problems of lower contrast and flicker of TFT liquid crystal display apparatus are ameliorated, and the power consumption of the backlight source is saved.