Abstract: Research methods, motion and internal force responses, and damage effect of metro tunnel structure when subjected to terrorist attack blast were discussed in this paper. Relevant protection measures were also discussed. It is found that the joint’s weakening effect was the primary cause for the stronger response of metro tunnel than the integral cast-in-place tunnel structure. The smaller the distance between explosive and the bottom of tunnel structure, the more obvious the displacement response of tunnel structure. An increase in the explosive yield not only enhanced the peak acceleration of tunnel structure, but also changed the direction of peak acceleration at the arch of tunnel structure. The protection against terrorist explosion in metro tunnel should be carried out from two aspects: reducing the probability of terrorist explosion accident and reducing the harm of terrorist explosion accident. The research on explosion response of metro shield tunnel structure under simultaneous and asynchronous initiation of asymmetric multiple explosion sources and the construction of a simple and practical design formula based on numerical analysis and machine learning algorithm prediction are worthy of attention in future research.