A data compensation method and apparatus for a liquid crystal display screen are described herein. Said method comprises determining a timing length ΔT′ from the last turn-off of the liquid crystal display screen upon turn-on of the liquid crystal display screen, and determining a mura data compensation table am called at the time of the last turn-off; determining a mura data compensation table to be called at the time of the present turn-on according to a pre-set time length T needed for stabilization of mura, mura data compensation tables corresponding to pre-set different time periods, said timing length ΔT′, and said mura data compensation table am; performing data compensation starting from the determined mura data compensation table to be called at the time of the present turn-on. By using said method for data compensation, an appropriate initial data compensation table can be determined to obtain a better compensation effect.