The thermal effect of 946 nm laser generated by laser-diode (LD) pumping the columniform Nd:YAG crystal is analyzed.After considering the quasi-three-level structure of the crystal and the distribution of transmission power in the cavity,a more actual temperature field in the crystal is obtained by revamping the heat conversion coefficient.The temperature of the crystal facet center becomes 246.7 ℃ from the previous 156.83 ℃ before revamping the parameter and increases 89.87 ℃.The thermal focal lengths before and after revamping the parameter are calculated and measured.The experimental result accords with the theoretical result basically.The method can be applied to the laser thermal effect research of quasi-three-level and three-level.The analysis and the result can be referred to the thermal effect research of the solid state laser end-pumped by the LD and the optimal design of resonant cavity.