Abstract: The electromagnetic radiation(EMR) signals generated by coal and rock failure have multifractal characteristics, in the positive order region, the width of the multifractal spectrum(ΔD_qc) tends to a stable value, which can represent the impact failure of coal and rock. In order to improve the prediction level of rock burst by EMR, by combining physical experiments with fractal theory, internal relations between ΔD_qc, and its impact tendency and remaining energy are studied during coal samples deforming and fracturing. The results show that ΔD_qc approaches a stable value with order form q increase from 2 to 7, and reaches the maximum at main rupture of samples; ΔD_qc has positive linear relationships with its impact energy index and remaining energy, and has logarithm relationship with its elasticity index. According to above study, quantitative classification index system of preventing rock burst by EMR is built. Using the above classification index system, the rock burst has been predicted accurately and successfully in 7251 working face.