In this paper, based on the analysis of the operation characteristics of laser diode end-pumped laser crystal, a thermal model of laser diode end-pumped Tm∶YAG crystal rod is established. The temperature field, thermal stress field and end-pumped crystal rod are numerically calculated by finite element method using heat conduction theory. The effects of laser beam with different laser energy distribution (circular Gaussian spot, elliptical Gaussian spot, circular flat top spot, square flat top spot), pump spot radius and Tm³⁺ doping concentration on the temperature field distribution and end surface shape variables of laser rod are analyzed, and plotted in three-dimensional distribution diagrams. The results show that under the stable state, if the laser diode pump power is 30 W, and the pump spot radius is 400 μm, the maximum temperature rise of the pump surface of the Tm∶YAG crystal rod with the doping concentration of 3.5at.% is 124.55 ℃, and the maximum stress of the pump surface is 209 MPa along the crystal z axis. The maximum heat shape variable of the pump surface is 0.888 μm. This study provides theoretical guidance for the design of Tm∶YAG laser.