A concise mathematical model was established to describe the radial temperature distribution of a metal-vapor laser tube with an axial temperature controller. The analytical solution of the radial temperature caused by thermal radiation and thermal conduction was obtained. The influences of the axial temperature controller on the discharge tube wall temperature and its radial temperature distribution were further calculated and analyzed. It is shown that the axial temperature controller can independently adjust the laser tube wall temperature, reduce the radial temperature gradient in some degree, and therefore improve the laser efficiency and stability.