The present invention discloses a method and system for detecting hidden ghost keys on a keyboard matrix. The keyboard matrix is composed of multiple rows crossing with multiple lines that form multiple key-locating positions. The method comprises: selecting multiple preset keys from the matrix; detecting ghost keys among the matrix based on the selected preset keys; selecting multiple examining keys from the preset keys and the detected ghost keys, based on that at least one ghost key is included in the examining keys; and determining hidden ghost keys based on the examining keys. The system detects ghost keys among the matrix via a preset key selecting unit and a ghost key detecting unit, which selects multiple examining keys via an examining key selecting unit, and determines hidden ghost keys based on the examining keys through a hidden ghost keys detecting unit.