The invention discloses a detection system and a detection method for aquatic dynamic target trail based on laser facula drift. The detection system comprises a laser, a CCD device and a signal processor. During use, the system is placed in water; the laser produces a unidirectional Gaussian beam; the CCD receives facula information; and the signal processor carries out the real-time treatment onthe output of the CCD, and the detection of the aquatic dynamic target trail is realized through the detection of the drift amount of the laser facula. The method comprises the following process: 1, measuring the drift amount of the laser facula for a plurality of times in a laboratory environment, and giving the standards for judging whether the target trail exists or not and the range for judging the target trail characteristics; and 2, carrying out the real-time measurement of the facula drift amount in a real water area, and comparing the sample average and sample variance of a plurality of times of the measured facula drift amount with the judgment standards and the judgment range so as to judge the existence and the characteristics of the target trail. The invention has the advantages of high detection precision and long detection distance and can be applied to the distant precise detection of surface vessels and underwater vehicles.