Abstract: Through LD double-end-pumped Nd:YVO4 laser crystal working character analysis,laser crystal thermal model and boundary condition according with practical working condition are built.Laser crystal interior temperature field and end-face thermal distortion field calculation equations are obtained by semi-analytical thermal analysis method,simultaneity all kinds of parameters affecting laser crystal temperature field distribution are all analyzed.All research results can be generalized to other laser crystals,and these research will be theoretically established for further research to effectively resolve laser-diode end-pumped laser system's thermal effect problem.