A mouse device is provided. The mouse device includes a battery module, a casing, and a control circuit. The battery module includes a first connection interface. The casing includes a second connection interface. The control circuit is disposed inside the casing and is electrically connected to the second connection interface. The battery module is detachably mated with the second connection interface through the first connection interface, and the battery module is exposed outside of the casing when being mated with the second connection interface. The control circuit obtains a power supply from the battery module through the second connection interface when the battery module is mated with the second connection interface.