Tunnel collapse has been a key issue in the tunnel construction field in China. A treatment method was formed for a collapse in Zhengyang Tunnel of Yuxiang highway based on the formation process of roof fall and the cause of collapsing accident in the construction. Self-stability of the surrounding rock above the tunnel is exacerbated by the affection of the thin overburden layer and weak stratum of rock with the groundwater in cranny. A channel is constructed around the mouth of collapse to strengthen the collapsing section and succeeded to seal the seepage water.