A optimization method is put forward for a wavelength stabilizer with dual Fiber Bragg Grating (FBG) used in 980 nm semiconductor lasers to meet the performance requirements of fiber amplifiers. The analytical expressions of transmittivity and reflectivity of dual FBG and the gain equations of the stabilizer are obtained by the coupled mode theory. The effects of the distance between the two gratings, the distance between laser front face and dual FBG, the period of refractivity, grating length,the refractivities and ambient temperatures of two gratings on the laser gain curves are analyzed.And these parameters then are optimized to achieve the best mode-stabilizing characteristics. The output spectral characteristics and powers of the uncooled semiconductor laser with dual FBG wavelength stabilizer are practically measured. Experimental results indicate that when the laser operates at 0～70 ℃, the wavelength shift is 0.5 nm, the Side Mode Suppression Ratio (SMSR) is more than 45dB, and the Full Width at Half Maximum (FWHM) is less than 1 nm. The optimized wavelength stabilizer with FBGs can satisfy the requirements of fiber amplifiers for uncooled semiconductor lasers, and can achieve high powers, long life, high reliability, small sizes, and low costs.