Research conclusions: For prevention of and avoiding high constructional risk in construction of high risky tunnel, the geological risky grade should be classified, the geological forecast in advance, measurement and control of wall rock and measures for alarm of prevention of disaster should be conducted well, more attention should be paid to the construction organization in unfavorable geological zone and the suitable construction program and measures should be adopted and taken, including reinforcement, excavation, support and lining of the wall rock in advance.