It is very important to choose a similar material which simulates rock mass correctly in geo-mechanics model test. In this paper, we introduce similar material research status and analyze the principle of selecting and compounding. According to the experiences of similar material research, we develop a new similar material (we call it iron barites sand cementation material, abbreviate IBSCM) through hundreds of compounding experiment. This similar material is made up of iron ore powder, barites powder, sand, rosin, alcohol and gypsum powder. Iron ore powder, barites powder and sand are main materials, the solution of rosin and alcohol is glue, and gypsum powder is regulator. Specimen mechanics tests show that different rock mass can be simulated by the model materials with different materials compounding. The new similar material is easy to buy and its price is cheap, and it has some advantages, such as high density, stable performance, easy dryness, and easy cutting. The new similar material can simulate a lot of rock mass, so it is an ideal similar material. At last, we apply this new type similar material to tunnel geo-mechanical model test and gain the ideal result.