Three microporous clay ceramics with uniform microstructure, adequate flexure strength of 11~23MPa, the same pore size about 4.2~4.6μm and different open porosities of 37%, 44% and 51% were fabricated from the powder blend of clay and slag by sintering. The microporous ceramics were machined into circular specimens, and then microporous ceramic irrigation emitters were assembled by installing the circular microporous ceramic specimens in plastic casings. By testing the hydraulic performance of the irrigation emitters, the effects of thickness and open porosity of microporous ceramic specimens and water head in irrigation pipeline on flow rate of irrigation emitters were discussed in detail, and then the relationships among flow rate of irrigation emitters, thickness and open porosity of microporous ceramic specimens as well as the water head in irrigation pipeline were fitted. According to the testing results, the flow rate of irrigation emitters was proportional to the water head in irrigation pipeline, and the linear relationship was not affected by thickness and open porosity of microporous clay ceramics. The thickness and open porosity of the microporous ceramic specimens had great effect on the flow rate of irrigation emitters. As the thickness of microporous ceramic specimens was increased, the flow rate of irrigation emitters was decreased gradually. Due to the power function relationship between the hydraulic conductivity and open porosity of microporous ceramics, the flow rate of irrigation emitters was increased exponentially with the increase of open porosity of microporous ceramics. As demonstrated from the result in this work, the microporus clay ceramics are promising for manufacturing irrigation pitchers and units for water seepage and filtration.