Build-up of leachate upon liner system due to failure of LCDS (leachate collectionand drainage system) often lead to various environmental accidents in hazardouswaste landfill. It is therefore significant to explore the mechanism and mainfactors of LCDS clogging in hazardous waste landfill. This study uses the original leachate from the hazardous waste landfill as drainage fluid, gravel as the drainage material, and selects vertical Column device to simulate the clogging role of drainage in actual hazardous waste landfill. The test study on non-clogging filtration layer of the device showed that: from the aspect of time, there are three distinct phases in terms of the development of drainage layer clogging, which are the beginning period of stable condition, and the metaphase of slowly clogging, and the final phase of sharp decline in porosity.From the aspect of space, the clogging were most serious at the inlet position, and it then decreased with the distance from inlet. In addition, the clogging extent is different among different height, and the difference become even more obvious as time. The experiment also indicates that the filter layer play a positive role to control the production of clogging, but a negative role to maintain its drainage capacity. With the presence of geotextile filter layer, the drainage flow are merely half of the flow without any filter layer. It is therefore suggested that filter layer should be installed above the drainage before careful consideration.