System and method used for maintaining safe distance

The invention provides a system used for maintaining safe distance. The system comprises a steering monitoring unit used for monitoring whether a vehicle steers or not, a distance measuring meter mounted on the vehicle and used for measuring distance between the vehicle and an ahead vehicle, a tachymeter used for acquiring traveling speed of the vehicle, an alarm and a controller used for receiving monitoring results of the steering monitoring unit. When the vehicle does not steer, the controller compares the distance with a preset safe distance according to the traveling speed of the vehicle, and when the distance is smaller than or equal to the safe distance, the controller controls the alarm to give to alarming signals; when the vehicle steers or the distance is larger than the safe distance according to the traveling speed of the vehicle, the controller controls the alarm not to give out the alarming signals. The invention further provides a method used for maintaining safe distance.