A timing control device for the display panel includes a control circuit. The control circuit is configured to generate a plurality of gate scanning control signals and a data transmission control signal. In response to that a display refresh rate changes from a first frequency to a second frequency, the control circuit adjusts the plurality of gate scanning control signals to generate a plurality of adjusted gate scanning control signals, or adjusts the data transmission control signal to generate an adjusted data transmission control signal, for driving a display panel under the second frequency as the display refresh rate.