A quasi-distributed fiber Bragg grating (FBG) sensor based on arrayed waveguide grating (AWG) is researched in theory and experiment. This sensor system has the advantages of easy operation, high response speed, low cost and high resolution. Its interrogating technique is based on the double-channel intensity–demodulating and the demultiplexing of an arrayed waveguide grating. The experimental result shows that the wavelength and temperature interrogation of the system have high linearity for the wide bandwidth of FBG, and the wavelength and temperature measurement accuracy reaches 2 pm and 0.2 ℃ under the effects of system stability and FBG crosstalk.