Abstract: Key technologies of uncertain XML twig pattern matching include uncertain XML document format,recognition of exclusive distribution nodes,calculation of the probabilities of witness tree and probabilistic threshold filtering.At present,binary structure join and holistic matching over uncertain XML can’t make full use of the characteristics of algorithms to solve key technology issues.In order to overcome this limitation,this paper proposes an uncertain XML twig pattern matching method based on sequence-based matching.We also analyze and prove key technologies of uncertain XML sequence-based matching.The theory research and the results of experiment show the effectiveness of this method.