The present disclosure relates to a bicycle locking device and method, and includes a fastening part including an inner fastening member positioned on an inner surface of a bicycle hub, and an outer fastening member positioned on an outer surface of the hub and coupled to the inner fastening member; a driving part coupled to one side surface of the outer fastening part and including a motor and an outer case; and a locking part including a pin case, a pin positioned in the pin case, a pin case cover coupled to the upper end of the pin case, and a first spring coupled to the pin case cover and the pin to support the pin so that the pin is pitchable with respect to the pin case.