Magnesium inorganic foaming materials containing a large number of closed pores inside were prepared by chemical foaming process, using magnesium based cementing material as base material, hydrogen peroxide as foaming agent, manganese dioxide as activator, calcium stearate as foam stabilizer and polyacrylamide as thickener. The effects of foam stabilizer and thickener on the apparent density, compression strength, flexural strength and pore structure of magnesium inorganic foaming materials were investigated. The crystalline phase of modified foaming materials was characterized by X ray diffraction(XRD). The experimental results show that the foam stabilizer and thickener not only affect the pore structure and foam formation of magnesium inorganic foaming materials, but also have a great influence on the crystal phase structure. When adding calcium stearate of 7‰(by mass) and polyacrylamide of 14‰(by mass), the compressive strength and flexural strength of magnesium inorganic foaming materials reach the maximum, the average pore size is smaller, porosity and roundness values are close to the ideal model of Kepler. XRD analysis shows that phase 3 crystalline diffraction peak strength of magnesium inorganic foam material modified by stabilizer and thickener is greatly weakened, while phase 5 crystalline diffraction peak strength becomes greater, which is the reason for the improvement of mechanical strength.