The invention provides a grinding device which comprises a center alignment. The center alignment component comprises a camera shooting component and an offset detecting component which detects the offset of the center of the wafer and the center of the maintain arm according to the information of picture shot by the camera shooting component. The offset detecting component detects the coordinates of more than three points on the external periphery of the wafer according to the information of the picture being shot so as to obtain the center of the wafer, and also detects the offset of the center of the wafer and the center of the maintain arm. The maintain arm is correspondingly corrected relative to the offset so as to load and place the wafer in the way of locating the center of the wafer to the center of the worktable being temporarily placed, a wafer moving component is set into one that can rotate in such a way: an absorption part carves a round arc track which passes through the center of the worktable being temporarily placed and the center of the chuck worktable, and the wafer moving component locates the center of the wafer to the center of the chuck worktable and relieves the absorption.