The present invention provides a video coding intra-frame prediction method and a video coding intra-frame prediction device, wherein, the method comprises performing a bidirectional prediction of an intra-frame left and upper direction prediction and an intra-frame right and lower direction prediction on the current coding block to obtain a prediction result; weighting the prediction result obtained. Since the distance between the current coding block and the reference prediction pixel is closer, thus the prediction correlation is high, thus it could achieve the high accuracy prediction of the intra-frame prediction during the process of video coding and thus could improve the coding efficiency.