Abstract: Tunnel reflection tomography (TRT) is a brand new method of tunnel geological prediction and it is play? ing an increasingly important role in tunnel geological prediction. As for the traditional TRT technique, a tunnel survey model is set up based on the geodetic coordinate system, which is time consuming onsite and affects construction progress. Based on an application of the relative coordinate measuring system in the geological advanced prediction of a power station tunnel, the results of geological prediction using geodetic coordinate measuring system and relative coordinate measuring system are compared and analyzed. The results show that the prediction effects of the two measuring systems are the same, with the one using the relative coordinate measuring system having better consistency with actual conditions.