The present invention discloses a storage device including a memory module and a memory controller. The memory controller includes a memory interface control unit, a command queue, a selecting unit, a buffer and a processing unit. The processing unit is configured to perform: generating a plurality of macro commands by combining a plurality of sequences of memory operation commands; writing the macro commands into the buffer; writing one or more than one operation parameter of the macro command corresponding to a host command into the buffer according to the host command outputted from a host; commanding the selecting unit to select the buffer as an input terminal; and commanding the buffer to output the macro command corresponding to the host command.