The present invention teaches a white balance method and device for a LCD panel. The method includes the following steps. Step S1 provides a LCD panel, including a mask-joint area and a non-mask-joint area outside the mask-joint area. The mask-joint area includes multiple first color resists arranged in an array, and the non-mask-joint area includes multiple second color resists arranged in an array. The first and second color resists are of different dimensions. Step S2 obtains a first white balance driving table for the mask-joint area and a second white balance driving table for the non-mask-joint area. Step S3 conducts white balance to the mask-joint area and non-mask-joint area using the first and second white balance driving tables, respectively. By applying different white balance driving tables to the mask-joint area and the non-mask-joint area, the white balance effect is improved, and the display quality of the LCD panel is enhanced.