［Purposes］ The paper aims to explore the evolution path and the law of collapse risk in tunnel construction, and provide theoretical support for preventing collapse accidents and ensuring construction safety. ［Methods］ Based on accident case analysis method, risk factors were identified from accident reports and related literatures, and 302 accident chains were extracted; Based on complex network theory, the importance, connectivity and evolution of network nodes were analyzed through the topological characteristic indexes of risk evolution network, key risk factors were determined and targeted countermeasures were proposed.［Findings］ Untimely support, unreasonable construction plan, instability of surrounding rock and poor geological condition are the key points of risk control. The average path length of the network is 2.18, and the clustering coefficient is 0.147.［Conclusions］ Each risk factor can evolve into a collapse accident after only 2 to 3 steps. Most of the risk factors have a low degree of interaction, but there is an obvious evolutionary relationship.