1. A liquid crystal display device, comprising: a liquid crystal panel; at least one source driving unit disposed on the liquid crystal panel and comprising at least one first fan-out line and at least one second fan-out line which are disposed alternately, wherein the at least one first fan-out line is configured to output a first polarity signal, and the second fan-out line is configured to output a second polarity signal; at least one demultiplexer disposed on the liquid crystal panel and electrically coupled to the first fan-out line and the second fan-out line, the demultiplexer comprising a plurality of buses, a plurality of first output lines, and a plurality of second output lines, the first output lines and the second output lines alternately disposed, each of the buses electrically coupled to one of the first output lines and one of the second output lines; and a plurality of pixel units, each of the pixel units comprising four sub-pixels, in the four sub-pixels of each of the pixel units in an N column, a first and a fourth of the sub-pixels respectively and electrically coupled to a first and a fourth of the first output lines, and a second and a third of the sub-pixels respectively and electrically coupled to a second and a third of the second output lines, in the four sub-pixels of each of the pixel units in an N+1 column, a first and a fourth of the sub-pixels respectively and electrically coupled to a first and a fourth of the second output lines, a second and a third of the sub-pixels respectively and electrically coupled to a second and a third of the first output lines, and N is an odd number greater than or equal to 1, wherein frames are made in sets of four, the first polarity signal has the same polarity in a first and fourth frames in each of the sets, and the first polarity signal has the same polarity in a second and a third frames in each of the sets.