A novel interrogation system for fiber Bragg grating (FBG) sensors with a tunable fiber Fabry-Perot (FFP) wavelength filter is proposed. The system combines a feedback loop arrangement and micro control unit (MCU), which integrates the closed-loop tracking mode into the scanning mode by varying the process of sawtooth voltage. As a result, the wavelengths of fiber grating sensor arrays can be interrogated; moreover, the wavelength of arbitrary FBG under dynamic conditions in the arrays can be tracked and then be locked. A strain resolution of <0.3-ustrain can be realized using this system.