The present disclosure relates to the technical field of liquid crystal display, and particularly, relates to a method for compensating impedances of data lines of a liquid crystal display. The method includes the following steps: a setting step of setting a memory and a subtracter; a measuring step of measuring the impedance value of a data line to be compensated, and inputting the impedance value into the memory; a calculating step of performing calculations with the impedance value measured in the measuring step through the subtracter, so as to obtain an impedance compensation value required by the respective data line; and a compensating step of reading out the impedance compensation value acquired in the calculating step through a data driving unit, and performing impedance compensation on the respective data line based on the impedance compensation value, in order to obtain a total load impedance for the respective data line. A uniform, satisfactory display effect can be ensured, with display defects, such as vertical black and white strips, color shift and the like, advantageously prevented.