The laser excitation and stimulated Raman scattering effect of the self-Raman laser are carried out in the same crystal compared to the conventional laser.Self-Raman laser has the characteristics of fewer components in the cavity,lower loss,lower threshold and compact structure,but it has serious heat effect.The optimum focusing depth of focal pumping spot in Nd∶YVO4 crystal of laser-diode-end-pumped self-Raman Laser is calculated by the mode matching function and the thermal lens model.The laser cavity is simplified by the thermal lens model,and the matching degree between the laser diode pump and the laser cavity mode can be quantified by the mode matching function.The correctness of theoretical calculation is verified through the experiment,and it is in good agreement with numerical simulation results.