Abstract: By using PowerSHAPE sculpting software, a scheme that adopts line, conic arc and cubic Bézier curve to describe the basic elements of direct slicing contour is presented. AutoSection macro is applied to create the direct slicing file with PIC as the standard interface of slicing data description. A direct slicing data processing software PDSlice is successfully developed and applied to the self-made HRPS-III selective laser sintering rapid prototyping system. The direct slicing method significantly improves the precision of micro-mechanical parts.