Abstract: Fulin tunnel is one of the important and complex tunnels in the Yun-Gui railway.With the comprehensive logging technology in the investigation of this tunnel,the three lateral resistivity,natural gamma,acoustic velocity,natural potential,the well liquid resistivity,temperature,hole diameter of those bore holes were tested.It provides the basis for the judging of formation lithology,rock integrity,the type of surrounding rock mass,anomaly zone,radiation,temperature,etc. In that,the precision of this tunnel investigation was improved.