Firstly, the paper introduced the principle of celestial navigation, and then put forward to detecting star images by using the shortwave infrared. Based on wavelet transform, a new algorithm of infrared small target detection is presented. The multiple scale wavelet analysis is employed, and adaptive threshold is determined to realize image de-noising in wavelet realm. The method has higher star detection accuracy, So as to improve the navigation precision of the system. The practices show that the measure request is contented.