Abstract: To study the mechanical properties and acoustic emission characteristics of coal and rock mass with different height ratios under different compound modes, RFPA^2D numerical simulation software was used to conduct the simulation researches for coal and rock mass. Results showed that the uniaxial compressive strength of the combination decreased with the increase of the ratio of the coal block in the combination, and the height ratio of rock to coal had a significant effect on acoustic emission energy. The higher the ratio of rock height in the coal-rock combination, the stronger the acoustic emission signals become, and the more acoustic emission energy it generated; the different combination of coal and rock would also affect the intensity when the coal-rock height ratio was the same, and the intensity of combination indicated the combinations of coal-rock, rock-coal, and rock-coal-rock in descending order. The analysis of the acoustic emission of the combination showed that the acoustic emission energy produced by the combination is proportional to the compressive strength. That is to say, the greater the compressive strength was, the more acoustic emission energy was produced.