The present disclosure relates to an electronic device and a data transmission system. A first electronic device includes a micro universal serial bus (USB) interface, a central processing unit (CPU) and a diode, wherein a pull-circuit for an identity (ID) pin of the CPU is coupled to a line between the ID pin of the CPU and an ID pin of the micro USB interface; the diode is coupled between the ID pin of the CPU and the ID pin of the micro USB interface, and is coupled between the pull-up circuit and the ID pin of the micro USB interface; the diode has a conducting direction from the ID pin of the CPU to the ID of the micro USB interface. With the present disclosure, the electronic device may be prevented from being damaged.