In order to reduce the step effects of the data processing in the rapid prototyping, improving the surfaces accuracy of production, a method of layer subdivision based on the boolen operation was put forward. The data of the layer subdivision was gotten by the computation of contour data of adjacent layers in two dimension, made by the rapid prototyping machine separately, which would reduce the impact of the step effects. Experimental results show that the method of subdivision of layer thickness based on the boolean operation can effectively improve the surface accuracy of parts.