P-sets (P stand for Packet) and P-matrix are novel and effective mathematical tools for studying dynamic information systems. In this paper, the concept of P-information mining is given by using the dynamic characteristics of P-sets and P-matrix structure. In addition, the reasoning theorem of P-matrix and the reasoning structure are given. Moreover, the information intelligent mining method under the condition of P-matrix reasoning is obtained. As the application, intelligent recognition of information image was shown.