Mohr-Coulomb strength theory has been used to analyses the elastic-plastic analytical solution of pressure tunnel in the field of rock engineering for many years. Because it could only solve the problems with one kind of material, the application of the theory was greatly restricted. In order to reflect the effects of stress redistribution, the stress adjustment coefficient is introduced in this paper to develop the elastic-plastic analytical solution of deep buried circle tunnel based on the unified strength theory. The applicability formulas is gained based on the critical pressures, which can be obtained in other situations or strength thoeries simplified by assuming the parameter value in the formula. An example is analyzed, and the yield range versus the inner pressure and stress distribution are presented. The results show that the parameter in unified strength theory has significant effects on the radius of plastic zone and the magnitude of stresses of the wall rock of tunnel, comparing with theory of Mohr-Coulomb.