To prepare the bottom ash geopolymer， municipal solid waste incineration bottom ash (BA), metakaolin and granulated blast furnace slag were selected as raw materials, and NaOH and water glass were adopted as alkali activators. The effects of different alkali content and BA content on compressive strength of geopolymer and hydration characteristics were mainly investigated. The results show that, when the alkali content reaches 7% (mass fraction, the same below), the reaction between excess sodium and active silicon, calcium and aluminum causes a large amount of low-strength N-A-S-H, which decreases the strength of bottom ash geopolymer. When the alkali content remains constant and the BA content reaches 80%, the strength of bottom ash geopolymer decreases substantially. Regarding bottom ash, its geopolymer system has a significant curing effect on heavy metal ions. Therefore, bottom ash geopolymer preparing by BA is of great significance for green recycling of municipal solid waste and environmental protection.