A laser diode (LD) corner-pumped Nd∶YAG electro-optical Q-switched laser with high efficiency and high stability that generates a 1.06-μm pulse laser output is designed and experimentally verified. Amplified spontaneous emission and parasitic oscillation are suppressed by using a low-doped Nd∶YAG crystal as a gain medium and a bonding Sm∶YAG crystal on both sides. The angular pump direct pumping method is used to increase the pump absorption optical path and thus increase the pump absorption efficiency of the gain crystal, and a zig-zag structure is used to improve the thermal effect. Under the conditions of a pump pulse energy of 383 mJ, repetition frequency of 20 Hz, and pump pulse width of 230 μs, laser output with a single pulse energy of 97.5 mJ and pulse width of 7 ns is obtained. The dynamic-to-static ratio of the output energy is 95.3%, the optical-to-optical conversion efficiency is 25.43%, the beam quality factors in two directions are Mx2 = 4.31 and My2 = 4.67, the change in Q-switched output energy within 140 s is less than 2%, and the energy instability of three consecutive working cycles is also less than 2%. The individual output energy attenuations are 1.59% and 2.11%, and the total output energy attenuation is 3.67%.