The invention relates to the field of automobile safety, and discloses a triggering method of automatic emergency braking system based on prediction, comprising methods for triggering primary alarm, secondary alarm and emergency brake, and meanwhile, the invention also discloses a movement locus predication algorithm of the current automobile and a front automobile. According to the invention, three stages after the system is started is divided according to three stages, namely, primary alarm, secondary alarm and emergency brake, according to the operation mode of the automatic emergency braking system, and meanwhile, a deceleration curve of the automatic emergency braking system is designed according to the difference of the secondary alarm manner of the system and the response characteristic of the vehicle brake system; and in the actual operation process, triggering of various difference stages of the automatic emergency braking system is realized by performing predication computation on the current vehicle and the front vehicle, and therefore, the triggering method has the advantages of being accurate and reliable in triggering, and low in erroneous judgement and missed judgement rate.