Based on the open pit to underground mining practice of Daye Iron Mine and the similar principles of model test, a new kind of similar material of underground caving mining model test which consists of iron ore powder, barite powder, quartz sand, unsaturated resin and gypsum is developed through a lot of material mechanics test. The physical and chemical characteristics of similar material from model test of Daye iron mine are studied. This similar material have been achieved national invention patent, patent number is 201210189082.X. The experimental results showed that 1. The physical and mechanical indexes of similar material vary in a large range and can meet the needs for underground caving mining model test．2. The shape of the similar material particle is abnormal, the content of spherical particles and the pore connectivity are less. 3. Because 70% ingredients of the similar material are calcium oxide and iron oxide, so the chemical reactivity is low, physical and chemical properties is stable in the natural environment.