A wireless testing system includes a main computer that controls a wireless module, a rotary mechanism, a measurement device, and an antenna. The rotary mechanism includes a rotatable seat controlled by the main computer to rotate about a first rotation axis, a support arm disposed on the rotatable seat, and a module rotating arm disposed on the support arm and positioning the wireless module at or in the vicinity of the first rotation axis. The module rotating arm is controlled by the main computer to rotate the wireless module about a second rotation axis. The antenna is substantially directed toward the wireless module. The measurement device is controlled by the main computer to control the antenna to receive or transmit a wireless signal.