A double Q-switcher-structured resonator that can completely compensate the thermally induced depolarization loss is designed to compensate thermally induced birefringence and thermal lens effect of solid gain medium to get higher output power from a 1 kHz laser diode (LD) side-pumped electro-optic Q-switched Nd:YAG laser. We add a resonator branch along the way of the depolarization direction of the polarizer on the base of a conventional Q-switch uncompensated structure laser and the output is from the Nd:YAG crystal side. The experimental results show that, in the same situation, the pulse energy of the improved laser is 74.7% higher than that of original one. At a highest input energy of 307 mJ, the pulse energy of 26.2 mJ is obtained. The optic-optic efficiency is 8.5% and the angle of divergence is about 1 mrad.