Abstract: A novel scan chain partition approach considering test power is presented.The peak test power and average test power of scan-based design circuits is modeled firstly, then the conclusion of test power are produced by the switching activity is obtained, considering the situation of multi-chain, to search the compatible cell from the input test set and make use of the compatibility of the scan cells, considering the layout information, distribute the scan cells to different scan chains, the multi-chain partition approach is based on Graph theory.The experiments on ISCAS89 benchmark show our approach's efficiency.The average test power and peak test power are reduced dramatically.