An active reflector is one of the key technologies for constructing large telescopes, especially for the millimeter/sub-millimeter radio telescopes. This report presents a new and substantial progress on the efficient laser angle metrology system for the active reflector antenna of the large radio telescopes, with a plenty of experiments based on a four-panel prototype system constructed by Nanjing Institute of Astronomical Optics and Technology (NIAOT). The test results prove that this technology is workable for sub-millimeter radio telescopes both in accuracy and time-response. Thus it can be applied to the reconstruction of the active reflector antenna in China and play a central role in promoting the new area of sub-mm radio astronomy.