The smallest rise-span ratio of large span cavern is an important reference to design the dimension of large span cavern. Based on both cavehoek constitutive model which can take some response characteristics during the excavation into consideration,such as the softening behavior of rock mass, dilation, volume expansion, density change, etc., and the critical strain which can reflect the influence of rock mass quality and UCS of the intact rock, the smallest rise-span ratio of 60 m long span caverns with different values of GSI, buried depth, lateral pressure coefficient of in-situ stress, structural planes, etc. were studied.The results show that: among the three factors of GSI value, lateral pressure coefficient and burial depth, the value of GSI has the biggest influence on the smallest rise-span ratio of large-span cavern, followed by the lateral pressure coefficient and burial depth. The better the rock mass, the smaller the ratio of smallest rise-span, and the minimum rise-span ratio is not linear with the lateral pressure coefficient and burial depth. The structure plane and UCS of intack rock also has great influence on the minimum rise-span ratio of large span cavern, especially the gently inclined structural plane which is not conducible to the arch forming of large-span caverns.