Abstract: Based on advanced theory of TGP ( Tunnel Geological Prediction) and actual engineering data, the authors applied informa?tion logic method to analyzing TGP 2D and 3D geological prediction results and mainly compared the similarities and differences in the aspects of the geological structure position, scale, surrounding rock classification and attutude. The results show that, if the surrounding rocks in front of the tunnel have no obvious difference in lithology, 2D and 3D geological prediction results are essentially the same. When the geological structures and tunnel are obliquely crossed, 2D and 3D are similar in the prediction results of tectonic attitude;however, 2D is advantageous in the surrounding rock classification prediction, and 3D is advantageous in the size and location predic?tion. Where the geological structure does not intersect with the tunnel side wall which is near the hole line excitation, 2D and 3D geo?logical prediction results are substantially different, and 3D geological prediction results are better than 2D prediction results.