The collected spectrum of the fiber Bragg grating (FBG) and the loss of the detected optical power are discussed with respect to the 3-dB bandwidth of a Fabry-Perot (F-P) type tunable optical filter (TOF), respectively. And the optimized parameters of the TOF are obtained consequently. It is demonstrated that the relationship between the transmission wavelength of the TOF and its drive voltage is nonlinear. A new method to compensate the nonlinearity of the TOF is proposed.The linear sweeping of the transmission wavelength of the TOF is achieved through modifying the drive voltage using interpolation algorithm. It is observed that the average error and the maximum error of the transmission wavelength are reduced sharply under linear fit. The dynamic strain sensing is realized by use of a reference FBG and moving averaging algorithm in this system. Fiber Bragg gratings (FBGs) have successfully been developed for using in optical fiber communication and sensing fields since 1989 [1] . One of the key issues in establishing an optical fiber sensing system based on FBGs is the selection of a suitable wavelength shift detection scheme [2] . Several interrogation systems have been proposed [3][4][5][6][7][8][9][10] . The methods are widely used for interrogating the wavelength shift of FBGs in fiber sensing systems [2][6][11] [12] . However, the parameters of the TOF are different in different references, and the nonlinearity of TOF is usually ignored. Little research on the proper design and nonlinearity compensation of the TOF for dynamic strain sensing systems has been performed.In this paper, the dynamic strain sensing system based on F-P type TOF is described first. Then the optimized 3-dB bandwidth of the TOF is obtained based on the collected spectrum of the FBG and the power loss with respect to the 3-dB bandwidth of the TOF respectively. It is demonstrated that the relationship between the transmission wavelength of the TOF and its drive voltage is nonlinear, which can be compensated by use of interpolation algorithm. Finally dynamic strain sensing is realized using this system.The schematic diagram of the dynamic strain sensing system based on F-P type TOF is shown in Fig.1. Wavelengthdivision multiplexing (WDM), time-division multiplexing (TDM) and space-division multiplexing (SDM) technologies are combined within this system simultaneously [13][14] .The two most important parameters of the F-P type TOF are free spectral range (FSR) and 3-dB bandwidth. They are also the key issues in design of the TOF for dynamic strain systems. If the FSR of the TOF is larger than the spectral bandwidth of the broadband source, the quantity of the FBGs is only restricted by the spectral envelop of the broadband source. The FSR of the TOF can be set to 90 nm, which is much larger than the bandwidth of broadband sources in most applications. Fig.1 The schematic diagram of the dynamic strain sensing system based on F-P type TOF