A test system comprising: a test board; at least one switch module of board under test connected with the test board, the test board including a first signal interface, a second signal interface and a third signal interface and a repeater, the second signal interface and the third signal interface being mutually connected by a signal cable, the first signal interface being connected with the repeater, the first signal interface being connected between the second signal interface and the third signal interface, the at least one switch module of board under test being connected with the second signal interface and the third signal interface, respectively, the at least one switch module of board under test including a plurality of relays; a control module connected with the at least one switch module of board under test by a control interface bus, the control module controlling the at least one switch module of board under test, the control module including a control power chip and a micro-controller, the control power chip being used to provide a direct current voltage for the micro-controller of the control module; and a test process module for receiving encryption result data tested by the test board, the test process module being a graphical user interface-personal computer, the test process module being connected with the control module and the first signal interface, respectively by at least two serial port buses, wherein the test process module is connected with the first signal interface to make the repeater set to enter a test mode, the test process module transmits a control signal to the control module, the control module converts the control signal into a serial control signal, and then the control module transmits the serial control signal to the at least one switch module of board under test, the control module controls the plurality of the relays of the at least one switch module of board under test to switch signal paths, the test board transmits result data to the at least one switch module of board under test, the at least one switch module of board under test transmits the result data to the control module through a serial return signal, the control module converts the serial return signal into a return signal, and the encryption result data is transmitted to the test process module through the serial return signal. a test board; at least one switch module of board under test connected with the test board, the test board including a first signal interface, a second signal interface and a third signal interface and a repeater, the second signal interface and the third signal interface being mutually connected by a signal cable, the first signal interface being connected with the repeater, the first signal interface being connected between the second signal interface and the third signal interface, the at least one switch module of board under test being connected with the second signal interface and the third signal interface, respectively, the at least one switch module of board under test including a plurality of relays; a control module connected with the at least one switch module of board under test by a control interface bus, the control module controlling the at least one switch module of board under test, the control module including a control power chip and a micro-controller, the control power chip being used to provide a direct current voltage for the micro-controller of the control module; and a test process module for receiving encryption result data tested by the test board, the test process module being a graphical user interface-personal computer, the test process module being connected with the control module and the first signal interface, respectively by at least two serial port buses, wherein the test process module is connected with the first signal interface to make the repeater set to enter a test mode, the test process module transmits a control signal to the control module, the control module converts the control signal into a serial control signal, and then the control module transmits the serial control signal to the at least one switch module of board under test, the control module controls the plurality of the relays of the at least one switch module of board under test to switch signal paths, the test board transmits result data to the at least one switch module of board under test, the at least one switch module of board under test transmits the result data to the control module through a serial return signal, the control module converts the serial return signal into a return signal, and the encryption result data is transmitted to the test process module through the serial return signal.