A scanning method and device, and a reverse scanning method and device in coding and decoding technologies are provided. The scanning method includes: receiving quantized transformed coefficients of a current block; obtaining a prediction direction of the current block; finding, according to the prediction direction, a scanning order corresponding to the prediction direction of the current block from a mapping relationship table of the prediction direction and the scanning order, wherein at least one scanning order in the mapping relationship table of the prediction direction and the scanning order corresponds to at least two prediction directions; and performing scanning processing on the coefficients by using the scanning order corresponding to the prediction direction of the current block. With the solutions of the present invention, the number of the scanning orders used in coding and decoding is decreased, and system complexity of a codec system is reduced.