A safe driving system having function of detecting heart rate variability is disclosed. The safe driving system having function of detecting heart rate variability mainly includes a detection display unit and a main control host. The detection display unit includes: a HRV detecting module, a display interface module, a first internal wireless communication module, a control button, a first processor, a power module and a voice management module comprising a microphone and an amplifier. The main control host includes: a mobile communication module, a satellite navigation system module, a second internal wireless communication module, a records preserving module, a second processor, a vehicle power module, a secondary power module, a power management module and an alarm module. The safe driving system having function of detecting heart rate variability is able to prevent the vehicle's driver from traffic accidents jeopardizing traffic safety due to drinking, taking drug, fatigue or an emergency occurred while driving.
