Earthenware is a kind of relic. By analyzing the earthenware, it is possible to conjecture about human activities at the time. Unfortunately, most of them have been damaged when excavated from the ruins. The traditional restoration method for earthenware is typically by manual work. It takes time-consuming and requires special knowledge in archaeology. Since there is always a mass of fragments mixed together color, pattern, and shape of fragments would be mainly used as clues. If entities are difficult to be restored, virtual objects restoration on the computer offers another possibility. In addition, virtual earthenware exhibits made by 3D models and replica earthenware exhibits made by 3D printers have educational values in historical museums and schools. In the present, in order to repair various of relics including earthenware, methods that assembly of earthenware pieces using computer-assisted have been well developed. According to the conventional method, adjacent fragments can be defined by the contour of the fragments and the cross-sectional shape of the rupture plane. Unfortunately, earthenware fragments are much different from other kinds of relic. Its curved surface and thin body make it difficult to calculate a 3D spatial posture. In our study, we proposed a spatial posture optimization algorithm for cylindrical pottery in the Jomon period which based on 3D measurement point cloud. This algorithm can meet all the adjacent fragments information, simultaneously. We have used this algorithm to repair several earthenware fragments successfully and effectively. It turns out to be an approach that deserves widespread use.