Research conclusions:The practice of Yichang － Wanzhou railway indicated that " The survey mode of long tunnel in complex － karst areas avoidance of geological hazards (risk) " could meet the normal railway survey program requirements，at the same time，try to expand the investigation way，add the phase of exploration，combine the exploration with geological forecast，create more opportunities to get more geological information，so the geological disasters could be analyzed comprehensively，and effectively prediction and advanced geological forecast in construction could be made，then，effective measures could be used to avoid geological risks．