The invention relates to the field of
data query, and particularly provides a medical
big data query method and
system based on dynamic desensitization, a terminal and a medium, and the method comprises the steps: collecting multi-source heterogeneous medical data, carrying out semantic normalization, constructing a
unique identifier of a patient, and generating standardized intermediate
plaintext data; constructing an adaptive isomorphic index
structure based on the data, constructing a semantic hash B + tree index for structured data, constructing a
feature vector index for
unstructured data, and dynamically optimizing index hierarchy and parameters according to
access frequency; and after a query request is received, the permission context is analyzed, intermediate
plaintext data is positioned and read by using the index, and a
differential privacy protection strategy is dynamically applied according to the access permission. According to the method, the problem of balance between
privacy protection and data effectiveness as well as between retrieval efficiency and storage cost in medical
data processing is effectively solved, and
data availability and access performance are improved while safety compliance is guaranteed.