In combination with a certain road tunnel instance Ningwu Highway，a working face rock ahead of forecast model is established. The prediction criterions include the Working face of rock radar images coefficient factor rock tunnel face conditions and the tunnel observation and analysis of geological factors are determined in the article. Their evaluation indexes are determined by the principle of which degree comes close and judged by experts. Finally the prediction results are came up through the fuzzy comprehensive evaluation and compared with the indexes of the degree of stability. Then it can make the prediction conclusion. The result shows that the model is convenient to use in practice very well. So it is proved that this prediction model is reliable.