Disclosed in the present invention is a wafer polishing system, at least comprising a polishing unit, which comprises a fixed working station and two polishing modules, wherein the polishing modules are located on two sides of the fixed working station; each polishing module comprises a polishing platform and a polishing arm, which can drive a wafer to move relative to the polishing platform, so as to implement a polishing process; the polishing arms of the polishing modules on the two sides are located in a diagonal direction of the fixed working station; and the polishing arms can respectively swing between the fixed working station and the polishing platforms to transfer the wafer, and movement regions of the polishing arms having an overlapping portion. By means of the present invention, the polishing arm of each polishing module is independently controlled, so as to achieve better stability and flexibility; and only one fixed working station is needed to achieve the cooperation of multiple polishing modules to implement the polishing process of single or multiple wafers, so that the movement path in the polishing process is greatly shortened, which minimizes the time of the transfer process and improves the polishing efficiency.