The　objective　of　this　paper　is　to　propose　a　technology　of　an　AC　short-circuit　current　controlled　fast　vacuum　breaking　in　a　short-arcing-time,　executed　by　a　fast　vacuum　circuit　breaker　(FVCB).　The　technology　comprises　of　a　determination　of　the　minimum　opening　velocity,　a　fast　prediction　of　the　short-circuit　current　zero　point,　and　an　optimization　of　the　Thomson　coil　actuator.　The　minimum　opening　velocity　of　3.2　m/s　is　determined　when　a　couple　of　cup-type　axial　magnetic　field　contacts　are　used　to　break　a　short-circuit　current　of　40　kA.　The　needed　duration　for　the　prediction　of　the　short-circuit　current　zero　is　4.0±0.4　ms.　The　optimization　of　the　actuator　aiming　at　minimizing　both　the　stored　energy　of　the　opening　closing　capacitors　and　the　moving　mass　of　the　transmission　parts　of　the　FVCB.　Terminal　fault　test　duties　of　T100s　and　T100a,　were　performed　on　a　prototype　of　363　kV/5000　A-63　kA　FVCB　in　order　to　verify　the　controlled　breaking　performance.　The　controlled　short-arcing-time　of　the　prototype　was　2.5　ms,　which　was　demonstrated　by　a　successful　breaking　of　the　short-circuit　current　of　80.6　kA　under　an　opening　velocity　of　4.5　m/s.　©　2020　IEEE.