Methods and devices are disclosed for panoramic video coding and decoding based on multi-mode boundary fill. If a predicted image block of a current image block is obtained by inter-frame prediction. The inter-frame prediction includes a boundary fill step of adaptively selecting a boundary fill method according to coordinates of a reference sample when the reference sample of a pixel in the current image block is outside the boundary of a corresponding reference image, to obtain a sample value of the reference sample. The panoramic video encoding and decoding method and device based on multi-mode boundary fill in the present invention make full use of the characteristic that horizontal image contents in a panoramic video are cyclically connected to optimize an image boundary fill method, such that the encoding can adaptively select a more reasonable boundary fill method according to the coordinates of a reference sample, thereby improving compression efficiency.