Abstract: In order to study the thermal effect of Nd:GdVO4 crystal pumped by variable radius LD bar in a resonator fiber,the theoretical values and experiment values were compared and they're largely in accord with those based on the new physics model with variable Gaussian radius.The results showed that the maximum temperature rise of 199.545℃ and the maximum thermal distortion of 1.33μm could be obtained in the center of the pump end surface when the Nd:GdVO4 laser crystal was pumped by a laser diode with an output power of 15W from the center of end face.This new method can be applied in the research of the other thermal problems of laser crystal and offer theoretical basis for solving the thermal problems in laser system effectively.