This disclosure relates to external defibrillators, expanders thereof and defibrillation monitoring systems. The external defibrillator can include a first human-computer interaction unit, a main control unit, a power module, and a first communication interface for transmitting data with an expander corresponding to the external defibrillator. The expander can include a host for collecting vital sign data, and a second communication interface, connected with the host, for transmitting data with the external defibrillator. The external defibrillator is portable for emergency rescue and also transmits data with the expander, thereby realizing various expanded functions.
