Remote monitoring for optical fiber grating sensing network making use of existing optical fiber communication network can not only avoid relaying sensing channel, thereby saving the cost, but also increase the sensing network flexibility. A new sensing data digitalization system is proposed based on arrayed waveguide grating (AWG). Quick digitalization of fiber Bragg grating (FBG) reflecting wavelengths which carry sensing information can be achieved. The operating principle and the main error source are analyzed. The sensing data framing module as well as the frame structure is designed. The simulation of a 3×3 fiber grating sensor network is carried out with OptiSystem/Matlab co-simulation approach. The accuracy of 1 ℃ in the range of -50 ℃~100 ℃ is realized, which can satisfy normal temperature monitoring requirement. The simulation results show the feasibility of the scheme.