The invention discloses a wavelength proposal optimization method in a G.653 optical fiber WDM system, relating to a working wavelength optimization method in a G.653 optical fiber wavelength division multiplexing (WDM) system. The system can efficiently reduce the FWM crosstalk of the wavelength proposal optimization method in the G.653 optical fiber WDM system. The method in the invention comprises the following steps: step 1, the system parameter of the G.653 optical fiber C band is set; step 2, the wavelength of the C band is optimized through calculation. The invention sets the system parameter and then calculates to get the wavelength proposal by utilizing the related parameters, thereby being able to select multiple wavelength number. The invention is able to simulate the actual optical parameters during parameters setting so as to improve the adaptability of the wavelength in the actual engineering.