Research results: It is necessary to take the different construction auxiliary measures from those for construction of tunnel main portal because of complicated landform of tunnel face, bad geological conditions and complicated stressed status of structure when the start tunneling is conducted for the tunnel with big cross section and cutting face. Some commonly used methods for start tunneling are presented, such as big pipe shed method, spreading cut and cover tunneling method, little pilot hole reverse construction method and counter pressure on strata method, and the analyses of start tunneling of the tunnel with big cross section and cutting face are made in combination with the construction practice in this paper.