In this paper we studied the operation mechanism of the flash lamp pumped,LiNbO 3 Q switched Nd:YAG laser and summarized the main factors that influence its output efficiency.Then we developed the laser design in order to improve the overall efficiency and reliability.As a result we reported the results of design and experiment of an high efficiency air cooled E O Q switched Nd:YAG laser.Its electrical optical efficiency is as high as 1.4% 2.0%.This kind of compact high reliability and high performance laser is suited to the needs of modern engineering applications.