Taking a practical project in northwest China as the background, plain soil is used as raw material, and po42.5 cement, PVA fiber, polymer (cold-dissolved PVA), soil curing agent and other modified admixtures are used.Test blocks are made in groups according to different mixing ratios. The mechanical properties of each group of test blocks are tested for compression resistance, bending resistance and splitting tensile strength, and the durability tests for water resistance, salt corrosion resistance, frost resistance and ultraviolet resistance are carried out. The results show that the fiber composite mud with 1% PVA fiber (length 12mm and diameter 20um)、0.125% sinovis liquid curing agent、3% polymer、10% cement and 86.875% soil has the best mechanical properties and durability.