Disclosed is a parallel intra prediction method for video data, including: dividing, by an intra prediction unit, pixels included in at least one prediction unit configuring a coding unit or a sub-coding unit so as to belong to any one of a reference pixel group and a prediction group; generating, by the intra prediction unit, reference sub blocks and prediction sub blocks, respectively, using reference pixels belonging to the reference pixel group and prediction pixels belonging to the prediction pixel group; performing, by the intra prediction unit, encoding processing on the reference sub blocks; and performing, by the intra prediction unit, encoding processing on the prediction sub blocks.