A parachuting safety device based on acceleration sensor is introduced.The device uses acceleration sensor to measure the changes of parachute’s acceleration

while the parachuter is jumping out of the plane

his vertical acceleration changes immediately

the timer of the device starts

and the time of the timer is computed for the falling height.When the falling height reaches appropriate height

the ejection device is triggered to eject the parachute and open it

then the parachuter begins to slow down and lands safely.