N-COUNT SIM 卡(一种将用户手机与通讯网络相联系的芯片，全称为用户身份识别模块卡片) A SIM card is a microchip in a mobile phone that connects it to a particular phone network. SIM is an abbreviation for 'Subscriber Identity Module'. SIM 卡(一种将用户手机与通讯网络相联系的芯片，全称为用户身份识别模块卡片)