An overcurrent detection device including: a current detection resistor that is connected in series to a main circuit and is configured to cause a potential difference at both ends according to a current flowing through the main circuit; a current detection circuit that includes a pair of connection portions and is configured to detect a potential difference between the pair of connection portions; a pair of voltage detection lines connecting the both ends of the current detection resistor to the pair of connection portions in the current detection circuit; and an erroneous detection prevention unit configured to prevent an increase in the potential difference between the pair of connection portions when at least any one of the pair of voltage detection lines has a connection failure.