The embodiment of the invention provides an identity information authentication method, a terminal, a server and a system, and the method comprises the steps: reading the identity document informationof a to-be-authenticated person; after the identity document information is authenticated, obtaining first face information of the to-be-authenticated person in real time; and based on a preset algorithm, carrying out portrait similarity comparison on the first face information and second face information in the identity document information, and when a comparison result exceeds a preset threshold, determining that the identity information of the to-be-authenticated person passes authentication. Through the embodiment of the invention, the hiding space of criminal offenders is reduced to themaximum extent, and potential safety hazards are reduced.