The problem that the workpieces with different sizes have different surface figures is studied in the continuous polishing process. The surface shape is a little concave and the peak valley (PV) value is 0.336 λ (λ = 632.8 nm) for the φ100 mm workpiece when polished in the 0.69 m continuous polishing machine. However, the φ48 mm workpiece is convex and the PV value is 0.336 λ . The Winkler′s hypothesis and the Preston equation are applied to study the surface shape of the workpiece, then the overturning moment of the workpiece is found to be the main reason for the surface inconformity. The theoretical analysis results show that to the round workpiece, when the product of the friction coefficient between the workpiece and the polishing pad and the resultant force from the separator to the workpiece is larger than 0.125 times diameter of the workpiece, the workpiece will turn to convex. The experiments of workpiece pressing, lubrication and moving down the supporting position of the separator is done. The results show that the consistency isn′t been improved by applying pressure on the workpiece; by adding lubricant to the polishing slurry, the consistency is improved as the surface PV of the φ48 mm workpiece is reduced to 0.128 λ ; and the inconsistency problem is solved as the surface PV of the φ48 mm workpiece is reduced to 0.058 λ and the shape is slightly concave when moving down the supporting position. The results indicate that the friction coefficient between the polishing pad and the workpiece shouldn′t be to large and the supporting position of the separator to the workpiece should as near to the polishing surface as possible in the continuous polishing process.