Abstract: Fiber Bragg grating sensor has the advantages of high sensitivity, anti-electromagnetic interference and corrosion resistance, which provides a new monitoring method for the safe and stable operation of transmission lines. In order to satisfy the demand of large-scale application requirement in transmission line monitoring, the test efficiency and reliability of FBG sensors need to be improved. Based on the core technology of LabVIEW and PXI bus of virtual instrument, this paper designs a test system for FBG sensor, and introduces the hardware composition and software implementation of the test system in detail. The system has high degree of automation and strong expansibility, which provides a strong support for the application of FBG sensor monitoring technology in transmission lines.