The traditional power demodulation method uses fiber Bragg grating (FBG) reflect ed light as the long period fiber grating (LPFG) incident light,which is unable to avoid the influence of the te m perature.This paper puts forward a kind of power demodulation scheme which could compensate the environment temperature of the LP FG,and the Bragg wavelength will be controlled by PZT driving voltage,making the FBG resonance wavelength always follow LPFG trans mission resonance wavelength,which could counteract the influence of the temperature.This demodulation scheme is suitable f or physical quantity measurement,in which the LPFG transmission spectrum shape changes,such as micro bending,lateral load ch aracteristics.From the LPFG transverse load characteristic test by this system,the results show that it has the same trend with optical spectrometer analyzer,it can always monitor LPFG resonant peak amplitude and realize the power demodulation with tem perature compensation,and the method is more suitable for dynamic demodulation.From the temperature characteristics of LPFG power demodulation experiments,it is verified that the demodulation system has the function of temperature compensation.