With the improvement of performance and reliability, high power semiconductor lasers have been widely applied in more and more fields. Thermal management is one of the most important issues effecting the optical-electrical performance of high power semiconductor laser. Compared with liquid-cooled techniques, conduction-cooled techniques have many advantages in some special applications because it could be adaptable for extreme environments, such as high temperature and low temperature. In this paper, a compact quasi-continuous wave (QCW) conduction-cooled high power semiconductor laser array was studied. The thermal behavior of the conduction-cooled semiconductor laser array with different structure and operation parameters were carried out using finite element method (FEM). The structure parameters of G-Stack semiconductor laser array was presented and optimized. Finally, A high power semiconductor laser array with superior performance was fabricated and characterized.