To accurately assess pollution status of the surface of luminescent port for navigation-aid lamps, this paper considers the impact of different pollutants on the difficulty of cleaning and proposes a pollution grade assessment method based on fusion weight method by fuzzy evaluation. The homogeneity was used as the discrimination standard to distinguish different pollutants in the blocked image. Fusion of subjective and objective weights through fuzzy evaluation, according to which the calculation formula of pollution degree was determined. Cleaning experiment was conducted on polluted samples according to the pollution grade method of this paper, and the cleaning rate is 93%. And the area method and entropy method will cause at least 32% and 29% waste of resources respectively. The area method does not consider the different cleaning difficulties of different pollutants. The pollution degree evaluation method proposed in this paper can distinguish pollutants and consider the subjective and objective influence of pollution assessment, which means the evaluation results are more scientific and accurate.