Abstract: Assembly-sets, consistency and integrality are highly required on assembly process of complex products, which needs to support visual assembly based on 3D Model in the case of BOM changes. By studying data relationship and changing process of multiple BOMs, a traceable static information model of BOM and a dynamic process model of BOM changing are established. A consumpable material distribution method from PBOM to MBOM based on path and part instance is proposed, and 3D coordinate dynamic operation is used to ensure the correctness of 3D model assembly and display. According to this method, the memory data structure is designed, and the system function is realized and verified, which proves that the method in this paper meets the practical application requirements.