A new method of the noise detection and a kind of adaptive weighted filter, based on the grey degree of incidence and the mean image or the median image, are proposed in this paper. At first, the grey coefficients of incidence matrix are calculated between the noise image and the mean image and the noise spots are distinguished according to the relations between the grey coefficients of incidence matrix and the threshold value TH. Moreover, taking the noise spot as the center, calculates the grey coefficients of incidence between the noise image and the mean image or the median image on 3x3 the template. Then, the values of the noise spot can be calculated according to the weighted mean value of the grey coefficients of incidence and the mean image or the median image, and realizes the adaptive weighting filter. Finally, the simulation testing has been carried on under the different noise level, and the denoising effect has been evaluated by using the signal-to-noise ratio, Peak Signal to Noise Ratio and the mean error objectively. The result shows that the proposed method may reduce the image fuzziness, preserve the integrity of edge and detail information, and has the good denoising effect.