Abstract: In order to study the uniqueness of the displacement back analysis of viscoelastic rock mass, an analytical solution of circular tunnel displacement in viscoelastic rock mass conforming to Maxwell model is derived according to the radial displacement of elastic rock mass, and displacement back analysis of circular tunnel displacement in viscoelastic rock mass is studied according to the parameter identification condition.The results show that no matter how many measuring points are arranged, all the five parameters cannot be uniquely analyzed.At least two parameters must be known before other parameters can be uniquely back-analyzed.Whether the lateral pressure coefficient is 1 and the ground stress is 0 has obvious influence on the displacement back analysis.With the increase of known parameters, the discernibility of parameters increases.The coefficient of ground stress and lateral pressure is the best, followed by elastic modulus, Poisson’s ratio and viscosity coefficient.The research results have certain guiding significance for the inversion calculation of rock mass parameters.