Abstract: A detection device has a detecting port, a leakage port, an oscillation circuit and a detection circuit. The detecting port is used for pluggably coupled to an object. The leakage port is electrically coupled to a ground loop. The oscillation circuit is respectively coupled to the detecting port and the leakage port, and used for generating an oscillation signal. When the detecting port is coupled to the object, electrons on the object are transferred to the leakage port via the oscillation circuit. The detection circuit is used for determining whether the detecting port is coupled to the object based on the oscillation characteristic of the oscillation signal.