A refitting mechanism for measuring a flatness value of a workpiece and refitting the workpiece includes a worktable, a refitting assembly, a measuring unit, and a controller. The refitting assembly is movably assembled to the worktable. The holding assembly is assembled to the worktable and adjacent to the refitting assembly for holding the workpiece on the worktable. The measuring unit is assembled to the refitting assembly. The controller is electrically connected to the refitting assembly, the holding assembly, and the measuring unit. The measuring unit measures a flatness value of the workpiece and transfers the flatness value to the controller. The controller compares the flatness value with a preset value range to determine whether the workpiece is qualified or not. When the workpiece is not qualified, the controller controls the holding assembly to hold the workpiece, and controls the refitting assembly to refit the workpiece.