Three kinds of magnesium-based foamed concrete with dry density grade A05 were prepared by chemical foaming with magnesium oxychloride cement, magnesium oxysulfide cement and magnesium phosphate cement as cementing materials respectively. By designing orthogonal tests, the influences of water/cement ratio, magnesium cement component ratio, retarder content, fly ash content and polypropylene fiber content on the compressive strength of three kinds of magnesia-based foamed concrete were determined, the action mechanisms of the important influencing factors were compared and analyzed, and the functional relationships between the specific strength of magnesium-based foamed concrete and the component ratio parameters of magnesium-based foamed concrete were established. The results showed that the primary and secondary factors affecting the compressive strength of magnesium oxychloride foamed concrete were the ratio of magnesium cement components>water/cement ratio>fly ash content>polypropylene fiber content>retarder content. The influence of various factors on compressive strength of magnesium oxysulfide foam concrete was the same as that of magnesium oxychloride foam concrete.The relationship between the factors influencing the compressive strength of magnesium phosphate foamed concrete was as follows: the ratio of magnesium cement components>retarder content>water/cement ratio>fly ash content>polypropylene fiber content. Different from magnesium oxychloride foam concrete and magnesium oxysulfide foam concrete, the content of retarder had a higher degree of influence. The component ratio of magnesium cement was an important index affecting the strength of magnesia-based foamed concrete. The compressive strength of magnesium oxychloride foamed concrete and magnesium sulfide foamed concrete had the same change trend with the increase of the component ratio of magnesium cement, both of which first decreased and then increased, while magnesium phosphate foamed concrete showed the trend of first increased and then decreased with the increase of the component ratio of magnesium cement. There was a power function relationship between the specific strength of three kinds of magnesium-based foamed concrete and the component ratio of magnesium-based foamed concrete.