With the rapid development of science and technology, big data technology is widely used
in the field of criminal investigation, and synthetic investigation, predictive investigation and active
investigation become the advantages of big data investigation. The use of personal information in big
data investigation is increasing day by day, which intensifies the security and protection of citizens’
personal information. At present, protection of citizens’ personal information in big data investigation
faced with the following difficulties: the expansion of the subject of infringement, the universality of
the object of infringement, the secrecy of the way of infringement, and the severity of the harmful
consequences. The reasons are the lack of legal regulation, the limitation of internal prevention
and control, the convenience of access channels, and the increase of leakage risk. Identification is
necessary to strengthen the constitutional legal regulation, perfect the internal prevention and control
mechanism, construct the pre-examination mechanism and establish the relief guarantee mechanism in
the investigation of the inherent aggression of big data to citizens’ personal information.