A retarder BCH developed from independent research was used to adjust the setting time of metakaolin slag geopolymer paste. Analysis of reaction heat, measurement of chemically combined water content and micro morphology analysis were used to verify the retarding effect of BCH. Results show that BCH can be used to effectively decrease the reaction rate of geopolymer paste and improve the compressive strength of solidified products. BCH has the best retarding efficiency with addition of 5.0%(by mass). At 20 ℃ and 80 ℃ the initial setting time is prolonged by 20.4 and 13.7 times that without the retarder respectively. At 80 ℃ the compressive strength at 3 d and 28 d is improved by 12.28% and 5.80% respectively. Alkali activated reaction at 20 ℃ and 50 ℃ has late and lower exothermal peak than that without BCH. Alkali activated reaction at 80 ℃ takes place during the period of 4.0～6.0 h and is later than that without BCH( for 0.2~1.0 h). When reacted at 80 ℃ for 1.0 h, the paste does not set, the product is covered with a layer of slurry, whereas the product of alkali activated reaction without BCH is compact solid.