To study the effect of activator properties and liquid-solid ratio on the working performance and mechanical properties of fly ash-based geopolymer, orthogonal test was performed. Test results show the working performance of fly ash-based geopolymer increases with the increase of liquid-solid ratio, however the strength decreases. The increase of activator concentration is not in favor of the performance of fly ash-based geopolymer but increases its strength. The mechanical properties and working properties of fly ash based polymers decrease with the increase of activator modulus. The strength of the fly ash-based geopolymer prepared in this research can be up to 61.35 MPa.