We present an interrogating technique employing a reformative arrayed waveguide grating without output waveguides in combination with a linear charge coupled device. A simple and effective data processing method called area equalized point is used to improve the system resolution. The simulation results show that the wavelength shift of a fibre Bragg grating with temperature can be precisely measured by this interrogation technique. The temperature accuracy and wavelength resolution of the sensor system are smaller than 0.08℃ and 0.8 pm, respectively. If the FBG 3dB-bandwidth is 0.2nm with the wavelength spacing between two adjacent FBGs of 1.4 nm, the temperature and wavelength errors caused by croestalk are respectively 0.01℃ and 0. 1 pm.