Breakage process of non-homogeneous materials has been implemented by mathematical experiment. In the simulation

random matrix stands for non-homogeneous artificial materials

and different picture element with varying lightness means different stress and acoustic emission （AE） state according to the corresponding relationship between the matrix and picture′s lightness. When an element is under a force beyond its critical value

breakage and AE will be produced. The change of the material under exterior force has been simulated and some AE parameters has been calculated. The simulation suggests that in the breakage process the trend of distance varies highly in line with energy and frequence of different AE

and so does the difference of these 3 parameters. Based on these results the formula of safety index and distance

energy

frequence

and that of safety index with latter 3 parameters′ difference have been established. Rock mass′ safety or breakage can be forecasted if these data has been normalized.