Vehicle active forewarning method, system and device based on millimeter wave radar

The invention discloses a vehicle active forewarning method, system and device based on millimeter wave radar. The forewarning method comprises following steps: obtaining vehicle driving information from each sensor; determining whether two vehicles are in a same lane based on the relative angle and relative distance between a vehicle and an objective vehicle; determining the longitudinal safe braking distance if the two vehicles are in a same lane, wherein Sw represents a warning safe distance, Sbr represents a safe braking distance, and R represents the relative distance; if R>Sw, the vehicle is in a safe driving state; if Sw>=R>Sbr, the vehicle is faced with a potential risk of collision; and if R<=Sbr, the vehicle is in an extremely dangerous state. By use of the forewarning method, system and device, the safety state of a vehicle is pre-estimated and early warning is made; accident rate is effectively reduced; the signal processing time is in milliseconds; the device is easy to install and maintain; good using effect is achieved.