The α-Al2O3 ceramic support was prepared by extrusion-forming and solid sintering methods. The effect of MnO2 addition on the performance of ceramic support was mainly studied. Mercury intrusion method, self-made pure water flux measurement device, three-point bending method, mass loss method, SEM and XRD were used to analyze the porosity, pure water flux, flexural strength, acid and alkali corrosion, surface morphology and crystal phases of the α-Al2O3 ceramic support. The results show that: MnO2 can form a solid solution Mn2AlO4 with alumina, which deforms the lattice and increases structural defects, thereby lowering the sintering temperature and promoting the sintering of the α-Al2O3 ceramic support. When the additive amount of MnO2 is less than 0.5%, the sintering is incomplete, and when the additive amount of MnO2 is more than 2%, the crystal grains grow differently. The optimum dosage of MnO2 is 1.5%, where the prepared support has a good performance with a porosity of 38.25%, the flexural strength is 80.3 MPa, the pure water flux is 657952 L/(m2·h·MPa), the weight loss rate of acid/alkali corrosion is only 1.22%/0.90%.