  The third Antarctic Survey Telescope array instrument at Dome A in
Antarctica, the AST3-3 telescope, has been in commissioning from March 2021. We
deployed AST3-3 at the Yaoan astronomical station in Yunnan Province for an
automatic time-domain survey and follow-up observations with an optimised
observation and protection system. The telescope system of AST3-3 is similar to
that of AST3-1 and AST3-2, except that it is equipped with a 14K~$ \times$~10K
QHY411 CMOS camera. AST3-3 has a field of view of $1.65^\circ \times
1.23^\circ$ and is currently using the $g$ band filter. During commissioning at
Yaoan, AST3-3 aims to conduct an extragalactic transient survey, coupled with
prompt follow-ups of opportunity targets. In this paper, we present the
architecture of the AST3-3 automatic observation system. We demonstrate the
data processing of observations by representatives SN 2022eyw and GRB 210420B.
