An adapter compatible with multiple types of plug pins includes a casing assembly, a bracket, a first conductive metal component, a second conductive metal component and a locking mechanism. A cavity is provided within the casing assembly. The bracket is detachably provided within the cavity. The first conductive metal component is provided on the bracket. The second conductive metal component is fixedly provided on the bracket. The locking mechanism is movably provided on the bracket, and includes a limiting part and an unlocking part. An outer side surface of the casing assembly is provided with a slot for slidable connection with a plug module.