According to the applicability of different strength criteria for calculating the loose circle, the theoretical formulas for calculating the loose circle of roadway surrounding rock are derived based on the elastic-plastic theory of surrounding rock by using the unified strength theory. Relying on the practical engineering, the thickness of surrounding rock loose circle of roadway is calculated theoretically by Mohr-Coulomb criterion, Hoek-Brown criterion and unified strength theory. And the theoretical calculation results are compared with the field test results. It is found that the thickness of loose circle calculated based on Mohr-Coulomb criterion is larger than the field test results, and the thickness of loose circle calculated based on Hoek-Brown criterion is smaller than the field test results. At the same time, the difference between the theoretical calculation thickness of the two methods and the field test result is large. However, the calculation of the thickness of the loose circle by the unified strength theory is close to the field test results. Therefore, the unified strength theory is applicable to the theoretical calculation of surrounding rock loose circle of roadway.