RPM要求。 A new method of adaptive slicing to point cloud surface was presented in combination with ordinary adaptive slicing in RPM and concept of structure RP model by point data slicing directly. Taking bar as the element, all points of layer were projected into some bars, got bar-point muster from it, drew contour from this layer and combined the judgment of linear relation about some bar-points by correlation coefficient. The area ratio of point cloud projection bar was defined as surface error, the relation between pile layer thickness and area ratio was established. By way of approaching worth with surface error, pile layer thickness was eventually determined. Finally, the experimental results showed that the algorithm is effective and fully satisfied the requirement of RPM.