AC blowing agent of 0.1%, 0.4% and 0.7% mass fraction was added to pellets of rich mineral paper. Foam rich mineral paper with 0.4, 0.2 and 0.8 thickness increasing rate was prepared through high speed cooling mixing, melting and mixture, pre-foaming extruding, hot press foaming, cooling, and cutting. The surface and cross section structure of the foaming rich mineral paper was observed with SEM. Micro-porous structures was founded on the surface; porous structures within the foam rich mineral paper was regular arranged; pore walls of which is stretched under the pressure generated by foaming. The results showed that the density of foam rich mineral paper is 16% to 30% lighter than rich mineral paper; when the AC blowing agent addition is 0.1%, the physical performance of foaming rich mineral paper is enhanced; when the additions of the AC blowing agent are 0.4% and 0.7%, its physical properties decline a certain degree.