A power system, a power module therein and a method for fabricating power module are disclosed herein. The power module includes a first and a second common pins, and a first and a second bridge arms. The first and the second common pins are symmetrically disposed at one side of a substrate. The first bridge arm includes a first and a second semiconductor devices, and the first and the second semiconductor devices are connected to each other through the first common pin and disposed adjacently. The second bridge arm includes a third and a fourth semiconductor devices, and the third and the fourth semiconductor devices are connected to each other through the second common pin and disposed adjacently. The first and the third semiconductor devices are disposed symmetrically, and the second and the fourth semiconductor devices are disposed symmetrically.