A test device and a method are provided in the invention. The test device includes a first connection interface, a storage device, a processor and a second connection interface. The first connection interface is coupled to a device under test (DUT) and obtains power information from the DUT according to a first instruction. The storage device stores the power information. The processor is coupled to the first connection interface and storage device, when the first connection interface is coupled to the DUT, sends the first instruction to the first connection interface, receives the power information from the first connection interface, and stores the power information in the storage device. The second connection interface is coupled to an external controlling system, sends the power information to the external controlling system and receives a test instruction from the external controlling system to test the DUT.