Abstract: The low cost filling of tailings is a key technological approach to breakthrough and solve the series problems of tailings environmental pollution and soft rock safety threats which seriously restricting the large-scale mining of China potash enterprises in Laos.By analyzing the characteristics of mining and filling environment of Laos solid sylvite deposits, the purpose of filling and the source of materials are determined.The limitations of traditional cementitious solidified materials are analyzed.The new type of cementitious solidified material is developed and its cementitious solidified effect is tested.The advantages of the new cementitious solidified material and its optimum selection of field filling methods are briefly analyzed.The cost expectation and prospect of promotion and application are given.The low cost filling technology of tailings which can strongly support large-scale, safety and environmental protection, and sustainable mining of China potash enterprises in Laos is overall studied.It is also of great important reference value for the development and utilization of the same type of sylvite resources in Thailand, the Republic of Congo and other regions.