A method for adjusting a liquid crystal display, includes: changing a voltage applied by a source circuit of the liquid crystal display, and measuring transmittance of the liquid crystal display at different values of the applied voltage; determining, according to a corresponding relationship between the applied voltage and the measured transmittance, a critical applied voltage that corresponds to a maximum measured transmittance of the liquid crystal display; and determining an operating voltage of the source circuit according to the critical applied voltage, and adjusting the applied voltage to the operating voltage.