In order to distinguish the icing from aluminum wing cover and measure the ice thickness,a near infrared multispectral detection method is presented. Firstly,the contrast value C is calculated by using an algorithm for ice detection based on the different reflectance spectra between water and ice in a certain wavelength band. Then,the threshold Cth of C is obtained by experiments. When C>Cth,it is considered that the ice exists,vice versa. The location of the icing on the aluminum wing cover is identified. A linear relationship between ice thickness and C is also proved by the experiment. According to the value of Cth and k,the ice thickness is calculated.