Fast clearance of short-circuit fault is vital to increase the transmission capacity of transmission lines of power grid and improve the transient stability of power system. The fast vacuum circuit breaker (FVCB) is a good candidate to achieve quick clearance of short-circuit fault. The objective of this paper is to design a new type of 72.5 kV single-break FVCB and verify its short-circuit breaking performance. A specially designed 72.5 kV vacuum inte

rrupter with floating shields and reduced mass of moving components technology is used as an arc extinguishing device

an electromagnetic repulsion mechanism is used as an operating mechanism and a specially designed oil damper is used as speed adjuster. For meeting the short-circuit current breaking requirements

the opening speed characteristics based on the anode discharge mode are quantified as the average opening speed

v

1

is 5 m/s in the stroke of the first 15 mm

and the average opening speed

v

2

is 1.59 m/s in the full clearance of 30 mm. The opening and closing time of the developed 72.5 kV fast vacuum circuit breaker is (1.2±0.04) ms and (18±0.20) ms respectively through the test; The short circuit breaking performance verification at 40 kA (rms) and 80 kA (rms) of test duty of T100s (b) is performed. The breaking result shows that the developed single-break 72.5 kV fast vacuum circuit breaker has met the breaking requirement of full arcing time interval defined in GB 1984—2014.