A device and a method for testing SAS channels which are applied to a plurality of pairs of SAS interfaces. The testing device includes a control terminal, a PCI-E microprocessor, a PCI-E-to-SAS adaptor, and a signal feedback module. The control terminal is used for selecting SAS channels and sending a control command; the PCI-E microprocessor is used for receiving the control command and sending a test signal to a PCI-E channel according to the control command; the PCI-E-to-SAS adaptor is used for converting a transmission signal between the PCI-E channel and the SAS channels; and the signal feedback module is used for connecting a first SAS interface to a second SAS interface in the SAS back plate. The PCI-E microprocessor compares whether the test signal sent to the first SAS channel is consistent with the test signal received from the second SAS interface.