A data storage connecting device includes a circuit board, a first connector, a second connector and a third connector. The circuit board has a first connecting end and a second connecting end. The first connector and a second connector are both disposed on the first connecting end and respectively at two sides of a long axis of the circuit board, a location of the second connector connecting with a data storage device being opposite to that of the first connector connecting with another data storage device. The third connector is disposed on the second connecting end for transmitting data from two data storage devices connected to the first connector and the second connector, respectively, via the circuit to a server device, or vice versa.