I have only seen the isolation card from some computer materials, but I have never seen it with my own eyes. As far as information is concerned, the isolation card is actually also called the network security isolation card. It is connected to the motherboard through the ide bus on one side of the card and the IDE hard disk on the other side. The connection between the internal network and the external network must pass this card, and the data can only access one partition at any time. From the development to now, the isolation card can be divided into two types according to the cut-off mode, one is to cut off the power supply and the other is to cut off the data. Power failure is an early product, because it will cause physical damage to the hard disk, and it has been replaced by the subsequent product-power failure data isolation card, which has become the mainstream product at present. The cut-off data isolation card is divided into IDE type and SATA type according to the access mode, which is the mainstream product at present. Because the ordinary isolation card needs to restart the system when it is used, it causes the problem of too long time. In recent years, the isolation card technology has advanced by leaps and bounds, and there are isolation cards that do not need to be restarted, which greatly shortens the time. At the same time, the new isolation card technology based on the principle of isolation card realizes the switching speed within a few seconds, which makes technical preparations for the isolation card to enter the personal field.