Given the problem of path redundancy by XML hierarchy itself and its inconsistent data and incomplete specification, the existing research results are used to analyze the deficiencies of structure dependency and numerical dependency, and the semantics are defined from the perspective of user semantics to obtain the inherent semantic association of data. This paper first defines the connotation of semantic constraints, and marks the user entities, and then gives the formal description of semantic dependency. Through the validity and completeness of the inference rules and semantic dependent closure sets, the completeness proof of semantic constraints is given. Finally, a complete theoretical system of semantic-dependent ontology privacy association is given, and the ontology semantic dependency closure set has a certain theoretical value and practical value of data mining and access authorization.