Porous mullite ceramic membrane supports were prepared by fly ash as the main raw material, with addition of loess and bauxite in the ratio of silicon to aluminium in the mullite phase (3Al₂O₃-2SiO₂), calcium carbonate as pore-forming agents and polyvinyl alcohol as the binder. The effects of calcium carbonate addition (0, 5, 10, and 15 wt%) and sintering temperature on the performance of prepared supports, including crystalline phase evolution, microstructure, porosity, flexural strength, and pure water flux, were investigated. The results shows that the increase in sintering temperature is beneficial to the formation of the mullite crystalline phase and improves flexural strength. When the sintering temperature reached 1200 °C and the calcium carbonate content was 5%, the porosity of the support was 46.3% and the flexural strength was 77.7 MPa. Based on the experiments, central composite experiments and response surface analysis were carried out to optimise the preparation conditions, and determine the optimum amount of calcium carbonate addition and sintering temperature. The results of the study are of reference value for the study of inorganic ceramic membrane support

Keywords: Ceramic membranes support, Fly ash, Porous mullite, Sintering temperature, Calcium carbonate