The weak geology is the major challenges of underground excavation in the geology of Nepal Himalayan. The existing tunnelling methods are designed from the various case studies and provide safe and economic design if applied to the similar geology. Due to the less study in the geology of the Nepal, the tunnelling methods being practiced worldwide are used during the tunnel construction in Nepal. The problems of tunnel squeezing, rock bursting and roof collapse are generally experienced problems due to weak geology and high overburden. The numerical analysis has to be performed with site specific rock mass properties for the stability of the tunnel. This paper reviews the construction methods of tunnel construction employed in the weak geology of Nepal through the case study of Kathmandu University Research Tunnel. The tunnel has been excavated manually and the support system based on the Q values in addition to the steel ribs are used based on the experienced form other hydropower tunnels. The support system combination of rock bolts, Steel ribs and shotcrete is suitable to withstand the stress and deformation in tunnel.