The invention relates to the technical field of automatic manufacturing, and discloses a position offset detecting method and a module, a grabbing position calibrating method and a grabbing system. The grabbing position calibrating method comprises the following steps of: capturing a detecting image of a workpiece to be grabbed in a present position through a camera in a preset grabbing position; identifying the center point of the workpiece to be grabbed from the detecting image; judging if the center point of the workpiece to be grabbed and the center point of the detecting image meet preset conditions; judging the offset occurs and the detecting image is mapped to a preset coordinate area of a preset coordinate system if the preset conditions are not met; respectively obtaining a workpiece center point coordinate and an image center point coordinate of the center point of the workpiece to be grabbed and the center point of the detecting image in the preset coordinate system; and calculating calibrating parameters of a grabbing position of the workpiece according to the workpiece center point coordinate and the image center point coordinate. The grabbing position calibrating method can automatically calibrate a grabbing path under the position offset condition of the workpiece to be grabbed to accurately grab the workpiece.