A method is for simultaneously operating the tray of an optical disk system and the front panel of the computer cabinet wherein the optical disk system is housed. In the method, the tray of the optical disk system is ejected immediately after the front panel of the computer case is completely opened when a tray operation instruction is issued and the front panel is currently at a close state. Additionally, the tray is retracted into the optical disk system before the front panel of the computer case is closed when a tray operation instruction is issued again and the front panel is currently at an open state so that the optical disk system may been closed inside a computer cabinet of the computer including HI-FI stereo. In the embodiment, the tray operation instruction is delivered via an output pin of the computer including HI-FI stereo and one of the reserved output pin of the optical disk system.