The use of outsourced filter materials is crucial for preventing blockages and ensuring efficient drainage in subsurface pipes. This study conducted a series of laboratory simulation experiments using a self-designed apparatus for subsurface pipes to address the technical bottleneck of low salt discharge efficiency, which is caused by the frequent blockage of these pipes. Based on a unified geotextile setup, four types of filter layers were established for subsurface pipes: a sand and gravel mixture, layered sand and gravel, a sand and gravel mixture combination with straw, and layered sand and gravel combined with straw, while a control group without any filter material. The effects of different filter layers on salt drainage efficiency and anti-silting effect of the subsurface pipes were systematically evaluated. The results indicated that: 1) The subsurface pipe with the layered sand and gravel treatment achieved the highest salt drainage rate of 47%. 2) When no filter material was used, a dense filter cake layer formed by soil particles on the surface of the geotextile. In both the layered sand and gravel treatment and the sand and gravel combination with straw, soil particles were retained within the fiber structure of geotextiles. 3) Soil characteristic particle size d₉₀ value above the filter material increased by 12.5%, 14.0%, 11.0%, and 10.5% with the use of a sand and gravel mixture, layered sand and gravel, a sand and gravel mixture combination with straw, and layered sand and gravel combined with straw, respectively. This effectively enabled the filter materials to intercept coarse particles while allowing fine particles to pass through, thereby promoting the formation of a highly permeable soil skeleton composed of coarse particles, such as sand particles, in the surrounding soil. The study reveals the impacts of the different filter layers on the efficiency of subsurface drainage for salt removal and their role in preventing blockages, thus provides a theoretical basis and technical support for utilizing subsurface pipe salt discharge technology to manage saline-alkali land.