This paper deals with the key technique of the portable vibrator system, whose correlation and tapper processing can restrain random noise and improve resolution greatly. The vibrator seismic source is of longer duration and generally lower amplitude than dynamite sources, with relatively less damage to ground and nearby structures. Field practice has demonstrated that the portable vibrator system can indeed serve as a nondestructive, controllable and high-resolution technique. This technique has already been applied successfully in the field of hydrology as well as civil and environmental engineering.