The invention discloses a disconnection detection device and a disconnection detection method. The disconnection detection device comprises a jack, a baseband chip, a level detection unit and a state detection unit, wherein the jack comprises a DETECT pin; the level detection unit is used for detecting whether an L AUDIO pin of a plug is connected with the DETECT pin, if the L AUDIO pin of the plug is connected with the DETECT pin, the level detection unit generates a trigger signal and transmits the trigger signal to the baseband chip, and the baseband chip starts the state detection unit after receiving the trigger signal; the state detection unit is used for detecting whether an MIC pin of the plug is connected with the DETECT pin, if the MIC pin of the plug is connected with the DETECT pin, the state detection unit generates a state value and transmits the state value to the baseband chip, and the baseband chip receives the state value and judges whether a call flash or an earphone is accessed through the plug based on the state value. The disconnection detection device and the disconnection detection method have the advantages that complexity of hardware circuits and software is reduced, complete machine cost is lowered, anti-shake time does not need to be considered, identification of the plug is not influenced when the plug is inserted rapidly or slowly, identification is accurate, and generality is strong.