With the rapid development of the national economy and the vigorous growth of highway construction and coal energy industry, soft muddy rock layers are often encountered during subgrade construction. Especially in coal mine tunnels, the base is mostly composed of mudstone, which can become severely muddy under the action of water and vehicle compaction, greatly affecting the quality of the subgrade and transportation. To solve the problem of solidification of muddy substances, this project has developed a geosynthetic clay liner (GCL) solidification technology, including muddy substance disposal additives, geosynthetic materials and geometric dimension optimization, as well as GCL solidification construction, which can achieve efficient solidification of muddy substances (including soft soil layers).