In this paper,a spatial temperature distribution model of laser crystal was established by means of heat conduction equation in case of the master-oscillator power amplifier (MOPA) configuration.On this basis,the thermal distribution of laser crystals in single-end-pumped and double-end-pumped amplifiers were numerically compared,concluding that the spatial temperature distribution at the laser crystal of double-end-pumped MOPA configuration was superior as compared to that of the single-end-pumped MOPA configuration.Furthermore,based on analyzing the influence of the parameters of the laser crystal and the beam waist radius of the pump source on the thermal distribution of the laser crystal,we employed a laser crystal with doped concentration of 02％ and length of 19 mm as well as a pump source with waist radius of 650 μm,constructed the double-end-pumped MOPA with uniform thermal distribution.