Abstract: To obtain similar materials of soft rock, the experiment selects river sand as aggregate, lime and gypsum as cement, iron sand as densification agent, glycerol as plasticizer, and borax combined with water as the anchoring material. It establishes orthogonal test scheme with 4 factors and 4 levels, and conducts the physical and mechanical experiment of similar materials. Through the range analysis, variance analysis and damage analysis of the test results, the study summarizes the effect law of component changes in similar materials on the physical and mechanical properties of the specimen. The results show that the main factors, which affect the density and mechanical properties of similar materials, are the proportion of river sand to iron sand and the proportion of glycerol to lime and gypsum, respectively. Under the maximum load, the specimen is basically damaged, with its damage value between 0.85-0.97. Based on the physical and mechanical properties of similar materials obtained by the paper, the optimal proportion scheme of similar materials can be designed, to meet the requirements of similarity test related to soft rock material, with the fixed target strength and similarity ratio.