Aiming at the actual working situation of circle laser crystal,according to the management mode of the circle heat capacity laser,the thermal conduction models of the pump phase and the cooling phase were established respectively based on the classic thermal conduction equation.Then the variable heat conduction coefficient is introduced to solve the equation,and the expressions of the temperature fields are obtained at single-end pump phase and cooling phase.And the influences of different spot radius and pump time on the crystal temperature field are analyzed.The results show that when the pump power is 60 W,the spot radius is 800 μm and the super-Gaussian order is 3,the thermal conductivity of Nd∶YAG crystal is regarded as constant and variable,the maximum temperature rise of the crystal is 164.84 ℃,195.58 ℃ at the pump end.The laser crystal has a size of Ф20 mm×10 mm,and has an absorption coefficient of 0.91 mm-1 for the incident pump light and 1.0 at% for the neodymium-doped ion.The calculated results are helpful to the optimization design and experimental study of LD pumped solid-state lasers.