A card connector, a card holder, and a terminal device, where the card connector includes a plurality of first terminals and one or more second terminals. The first terminals are arranged to form a first card access area that installs a first card, and the first terminals are configured to be electrically coupled to the first card. The one or more second terminals are distributed on a periphery of the first card access area, the first terminals and the one or more second terminals form a second card access area that installs a second card, and the first terminals and the one or more second terminals are configured to be electrically coupled to the second card.