A new chirped fiber Bragg grating(CFBG) interrogator is proposed with triangular spectra for the grating sensor.The phase delay of the wavelength of the light reflected by the sensing grating is determined by the intensity detecting and phase detecting synchronously.The intensity detecting determines the interval of the phase delay,and the phase detecting determines the phase delay in the interval.So the has higher precision and broader wavelength span.A CFBG with triangular and broad-band spectra is fabricated.The simulation results are shown when the grating acts as interrogator in the FBG sensor systems.