Embodiments of the invention provide an RF-MEMS single-pole double-throw switch and a micro-strip antenna array. The RF-MEMS single-pole double-throw switch comprises a substrate, a signal line, a common ground terminal and at least two micro electro mechanical switches, wherein the signal line comprises a first branch signal line and a second branch signal line, which are respectively provided with a first disconnection area and a second disconnection area; the common ground terminal covers the first disconnection area and the second disconnection area, and the common ground terminal is connected into a whole through the first disconnection area and the second disconnection area; and each micro electro mechanical switch comprises a switch beam and an electrode plate, and the micro electromechanical switches are respectively arranged in the first disconnection area and the second disconnection area. The electric potential of the whole command ground terminal can be equal without an extra air bridge. Therefore, a structure of the RF-MEMS single-pole double-throw switch is simplified, and the cost is reduced.