By solving heat conduction equation,the distribution of temperature field in laser crystal and the thermal distortion of laser crystal pumped-end were investigated,when the crystal with circular cross-section was end-pumped by laser diode. Analyzing the working environment,the more practical thermal model of laser crystal was built. The analytical expressions of temperature field and thermal distortion were obtained. Through numerical calculation,the influence of heat conduction conditions of crystal ends on temperature field and thermal distortion were studied. It was found that the widely used adiabatic conditions on laser crystal ends are not practical,and the proposed heat conduction conditions in the paper are more accurate. The results show that when parameter σ equals 0,0.6 or ∞,the maximum temperature rise in crystal is 165.2,135.7 or 40.1 ℃,and the maximum thermal distortion of crystal pumped-end is 0.66,0.55 or 0.22 μm,respectively.