Based on the needs of permeability test of slurry concretion body and grouting concretion body and their block performance test to the pollutants, one kind of permeameter with flexible wall was developed which is air-proofed by all round pressure, and got the patent in China. Permeability coefficient tests were made on S, N and Z three slurry concretion body samples in different seepage pressure and different all-round pressure, the results of permeameter with flexible wall and NAN-55 permeameter were compared, and landfill leachate filtration test was also conducted. These tests proved that the permeameter with flexible wall has little requirement for slurry concretion body samples with good airproof, the error was less than 119×10-7 cm/s and the precision could be conformed to the standard. This article has selected flexible latex film for wall around the sample and made the sample air-proofed by air pressure or water pressure. Adjusting range of seepage pressure was 10-1000 kPa, all-round pressure was 10-1500 kPa. The diameter of sample could be 618 mm or 101 mm, and the length between 20-150 mm, it was convenient to test permeability coefficient of slurry concretion body, grouting concretion body, and block performance of the body to the pollutant in sewage, and helpful to develop anti-seepage slurry.