The invention relates to a dual-mode 8 access address calculation method. The method comprises the following steps: selecting a corresponding dual-mode 8 access address calculation formula according to the type of a matrix; configuring a corresponding base address and an offset address according to the scale of the matrix before transpose; generating 4 or 8 valid addresses by calculation, and reading a group of data of the matrix before transpose by the addresses; configuring a corresponding base address and an offset address according to the scale of the matrix after transpose; generating 4 or 8 valid addresses by calculation, and reading a group of data of the matrix after transpose; adding 1 to the base address to serve as a new base address; judging whether the transpose of the matrix is accomplished, if the judgment result is positive, executing the next step, and otherwise, returning to step 3; and terminating the matrix transpose process. By adoption of the dual-mode 8 access address calculation method provided by the invention, the real number matrix transpose execution period can be shortened by single-word dual-mode 8 access address calculation; and the imaginary number matrix transpose execution period can be shortened by double-word dual-mode 8 access address calculation.