A method, a system and a terminal for identity authentication, and a computer readable storage medium are provided. The method for identity authentication includes: acquiring a facial image of a person to be authenticated, and determining from the facial image facial feature information of the person to be authenticated; determining a suspected object using a face authentication platform according to the facial feature information of the person to be authenticated; acquiring a human body image of the person to be authenticated, and determining from the human body image a plurality of skeleton key points of the person to be authenticated; converting the skeleton key points into feature data; and recognizing an identity of the person to be authenticated according to the feature data of the person to be authenticated and information of the suspected object.