A data accessing method of a switch for transmitting data packets between a first source node and a first target node and between a second source node and a second target node includes: transmitting a data packet to the switch via at least one of the first communication link and the third communication link and configuring the control unit to store information contained in the data packet into the storage unit; and retrieving the information contained in the data packet from the storage unit via at least one of the second communication link and the fourth communication link. The first source node, the second source node, the first target node and the second target node share the same storage blocks.