During the construction of Shuanggang navigation and power junction project along the Xinjiang River, the cofferdam filling has the characteristics of low strength and low permeability. Because of the large scale of the cofferdam on site, considering the size of the model slot, the similarity of this model test is large, and the shear strength index and permeability coefficient of the corresponding analogous materials are very low. Talc, barite powder, silty sand, sodium bentonite and foams were used as raw materials. Based on orthogonal test, analogous materials were prepared for model test of the cofferdam. The density, undrained shear strength and permeability coefficient of analogous materials with different ratios were obtained through density test, vane shear test and penetration test. The results show that the undrained shear strength of the material is low, and the other parameters are widely adjusted, which can meet the requirements of most model tests on analogous soil materials and is especially suitable for simulating soft soil under water environment in model tests. The outcome can provide reference for the selection of analogous materials in other model tests.