  The Five-hundred-meter Aperture Spherical radio Telescope (FAST) was
completed with its main structure installed on September 25, 2016, after which
it entered the commissioning phase. This paper aims to introduce the
commissioning progress of the FAST over the past two years. To improve its
operational reliability and ensure effective observation time, FAST has been
equipped with a real-time information system for the active reflector system
and hierarchical commissioning scheme for the feed support system, which
ultimately achieves safe operation of the two systems. For meeting the
high-performance indices, a high-precision measurement system was set up based
on the effective control methods that were implemented for the active reflector
system and feed support system. Since the commissioning of the FAST, a
low-frequency ultra-wideband receiver and 19-beam 1.05-1.45 GHz receiver have
been mainly used. Telescope efficiency, pointing accuracy, and system noise
temperature were completely tested and ultimately achieved the acceptance
indices of the telescope. The FAST has been in the process of national
acceptance preparations and has begun to search for pulsars. In the future, it
will still strive to improve its capabilities and expand its application
prospects.
