A common voltage generating circuit is applied to a liquid crystal display circuit and includes M common voltage generating sub-circuits. The liquid crystal display circuit includes a data-driving chip, a row-driving chip, a thin film transistor (TFT) array, and a liquid crystal unit array corresponding to the TFT array. The row-driving chip is used to for opening the TFT array row-by-row through scanning lines. The data-driving chip is used for charging one row of the liquid crystal unit corresponding one row of TFT through data lines. N input terminals of a first common voltage generating sub-circuit respectively connect with adjacent N data lines output from the data-driving chip, an output terminal of the first common voltage generating sub-circuit connects with a common terminal of the liquid crystal unit corresponding to the N data lines, N is an even number.