In response to the “carbon peak and neutrality” policy of energy saving and emission reduction, in the present paper, geopolymers were prepared with metakaolin and blast furnace slag as raw materials. The compressive strength was used as the index to optimize the preparation conditions and to explore the factors affecting the strength of geopolymer based on metakaolin. The optimum mixing ratio of geopolymer was determined by orthogonal test. The metakaolin fractions calcined at different temperatures were analyzed by thermogravimetry and XRD. The research results show that when the calcining temperature of kaolin is 800 ℃, the optimum mixing ratio of geopolymer based on metakaolin is that the mass ratio of sodium hydroxide to sodium silicate is 6.5∶1 and the mass fraction of activator is 14.2%. Under these conditions, the 28 d compressive strength of the geopolymers reaches 46.6 MPa. The compressive strength of the geopolymer based on metakaolin increases with the addition of the mass fraction of activator, and increases first and then decreases with the increase of the mass ratio of sodium hydroxide to sodium silicate, and increases first and then decreases with the increase of kaolin calcination temperature.