In this study, a high-accuracy wavelength interrogation chip for Fiber Bragg Grating sensing is designed and implemented based on photonic integration technology. A compact wavelength interrogation system is constructed by monolithically integrating an arrayed waveguide grating with a germanium-silicon photodetector on a silicon on insulator platform. Finite-difference eigenmode and time-domain finite-difference methods are used in the design to systematically simulate the waveguide structure and the tapered coupling structure to achieve efficient optical field transmission and improve the absorption efficiency. Experimental tests show that the average insertion loss of the integrated chip is lower than 3 dB, and the channel crosstalk is lower than -22 dB. In the actual interrogation test of the FBG system, it exhibits a wavelength interrogation accuracy of 13.58 pm with a wavelength resolution of 4.3 pm. It proves the combined advantages of the chip in terms of size integration and interrogation performance, and is suitable for structural monitoring and biomedical sensing.