Abstract: Due to the lack consideration of product assembly spatial structures, assembly model search can not obtain results as expected.A retrieval method based on product spatial structure matching was proposed to solve this problem.A new algorithm of similarity evaluation of assembly models, which is based on spatial point set matching method, was built.The assembly model was represented with spatial feature point set, and a reasonable assembly model similarity was obtained according to part attribute similarity and part spatial position similarity.The experiment result indicated that this method can effectively implement the similarity searching of product assembly models.