Abstract：Technique of geological prediction ahead is one of the important parts in tunnel informational construction，especially for important projects，it is very significant with accurate and instantaneous geological prediction. Many have been studied from different angles with new techniques and methods. Lots of methods have been acquired such as ground penetrating radar(GPR) and tunnel seismic prediction(TSP). However，engineers cannot obtain satisfied results from single prediction method. Based on this background，geological prediction techniques are discussed and studied. And then，according to ground geologic survey，GPR and TSP，a synthetic geologic prediction method is put forward. The problems such as inaccurate and even improper geological prediction，which were found during geological prediction，are discussed and the merits and weaknesses of the three main methods are analyzed. The synthetic prediction method is discussed in detail. And then the realization process is put forward. Finally，the application of the synthetic geological prediction method to the geological prediction ahead of Guangrenling tunnel is illustrated. Two faults are forecasted successfully and the precision reaches 95%.
