Sulfur hexafluoride(SF

6

)gas is a greenhouse gas that is highly harmful to the atmospheric environment and is widely used in gas-insulated power equipment.A new SF

6

gas detection system based on hollow waveguide fiber(HWF)is proposed

which can be used for low volume fraction of SF

6

gas leakage detection.Firstly

light emitted by the carbon dioxide(CO

2

)laser is collimated

attenuated

and coupled into the hollow-core fiber.Then

the light that has undergone an absorption reaction with the gas in the

hollow cavity is detected by a detector.Finally

the signal is processed by digital filtering based on LabVIEW and digital dual-phase lock-in amplification.SF

6

gas with volume fractions of 0.5×10

-6

2.45×10

-6

4.9×10

-6

and 9.92×10

-6

are detected.The experimental results show that the detection limit of the detection system can reach 0.5×10

-6

the detection error of the SF

6

gas volume fraction is less than 1%

and the repeatability test shows that the detection system has high stability.