An efficient and eco-friendly oil-water separation strategy is urgently needed to solve the problem of oily sewage due to the frequent occurrence of oil leakage accidents. Diatomite porous ceramics were firstly prepared by a foaming-gelcasting method, and then superhydrophilic-oleophobic diatomite porous ceramics were prepared by a simple vacuum impregnation method with the diatomite porous ceramics as a matrix and fluorine-containing polymer (Capstone FS-50) as a modifier. The effect of sintering temperature on the phase composition, microscopic morphology and physical properties of porous diatomite ceramics was investigated and the influence of CS-50 concentration on the oil contact angle and chemical stability of the surface of modified diatomite porous ceramics was also analyzed. The mesopore structure of disk-like diatomite becomes more and more blocked, the porosity of the porous samples decreases from 84.3% to 81.6% and the compressive strength increases from 0.93 MPa to 2.01 MPa as the sintering temperature increases from 1 100 to 1 200 ℃. The oil contact angle of the prepared modified diatomite porous ceramics firstly increases and then becomes stable with increasing Capstone FS-50 concentration. At the concentration of Capstone FS-50 of 5%, the oil contact angle of the porous ceramic is high up to 138°, and whose water contact angle is about 0°. In addition, the modified diatomite porous ceramics still maintain hydrophilic and oleophobic after soaking in acid, alkali and salt solutions, thus exhibiting superior chemical corrosion resistance.