The present invention discloses a testing device and a testing method. The testing device is used for improving testing effects and testing efficiency. The testing device provided by embodiments of the invention comprises a dark box and a reflecting component, a sealed cavity body is arranged in the dark box, an opening is arranged in a surface of the dark box, and the opening communicates with the cavity body. The reflecting component is arranged in the cavity body, a reflecting surface of the reflecting component is opposite to the opening, a reflecting surface is used for reflecting test optical signals emitted from the opening, and the test optical signals are optical signals emitted by an electronic instrument to be tested. Therefore, the electronic instrument emits the test optical signals, and the test optical signals enter the cavity body of the dark box from the opening in the dark box, irradiate to the reflecting surface of the reflecting component and are reflected out of the cavity body of the dark box from the opening. Functions of the electronic instrument can be tested through the reflected test optical signals. The testing device is used for testing the electronic instruments, so that testing effects and testing efficiency are improved.