In order to meet the application requirements of military long-distance laser rangefinders for solid-state lasers with small volume and high peak power, a small air-cooled LD-pumped Nd∶YAG solid-state laser was designed by using short cavity length and orthogonal polarization electro-optic Q-switched technology. The prototype was verified by experiments. The results show that, the laser with weight of 630g, repetition frequency of 20Hz, output energy of 85mJ, pulse width of 3.9ns, laser peak power of 21.8MW and beam divergence angle of 1.9mrad meets the requirements of miniaturization and high peak power. The laser has strong environmental adaptability and has been applied in engineering.