The invention relates to a connector shell, a connector shell assembly, a connector contact piece and a connector in the field of connectors. A contact piece slot is formed in the connector shell and is used for the contact piece to insert, more than two locking structures are arranged on the connector shell in a plug-out direction of the contact piece and are used for matching with the contact piece in a blocking way, at least one of the locking structures is formed from a locking arm arranged on the connector shell, the locking arm is provided with a locking position and an unlocking position, the locking position is used for entering the contact piece slot and is matched with the contact piece in a blocking way, and the unlocking position moves towards an outer side of a groove wall of the contact piece slot and is used for removing blocking matching with the contact piece. In the connector shell, on the basis of matching an existing connector shell and the contact piece in a clamping way, a second-layer locking structure formed by blocking matching of the locking arm and the contact piece is additionally arranged, so that the contact piece can bear relatively large plug-out force, and the safety performance of the connector is improved.