The present invention relates to a method of extending a pixel gray scale. The secondary gray scale levels with different charging times and the same gray scale voltage are formed by controlling a charging time of the gray scale voltage of every primary gray scale level and refining the level, wherein, the gray scale voltage of the every secondary gray scale level is the same as that of the corresponding primary gray scale level, and its charging time corresponds to the secondary gray scale level. The primary gray scale level of the display pixel of the liquid crystal panel is extended by using this method and the disadvantage of the imperfect display brought forward by the control method using frame rate in the prior art is overcome. The present invention further provides a drive method of controlling the pixel charging time and a drive apparatus thereof, which realizes the pixel gray scale extension by controlling the charging time of the pixel capacitance. It overcomes the disadvantage that a grid strip may be formed visually using the characteristic of the visual retention and the visual inertia of the human eyes while largely increasing the number of colors that can be displayed.