为提高船舶夜航光环境评价精度，从而更好地治理海上光污染，保障船舶夜航安全，在充分考虑光环境质量等级划分时边界的模糊性和不确定性的基础上，利用云模型的不确定推理特性和物元可拓理论兼具定量、定性分析的优点，提出一种基于云模型改进物元结构的船舶夜航光环境评价模型：采用层次分析法、熵权法以及均方差法确定光环境评价指标权重，从而弱化主观因素的影响；构建光环境质量标准云物元模型，计算待评物元与标准云物元模型的关联度，通过信息熵理论确定光环境质量等级；根据信息熵理论定义了置信系数，使得评价结果的可信度易于定量计算.实际算例验证了该模型的有效性和优越性.

In order to improve the evaluation precision of light environment for ship night navigation, so as to better control the light pollution at sea, and ensure the safety of ship’s night navigation, on the basis of considering the fuzziness and uncertainty of boundary in the classification of light environment quality grade, a light environment evaluation model for ship night navigation was proposed based on improved cloud matter-element structure by using the uncertain reasoning characteristics of cloud models and both advantages of quantitative and qualitative analysis of matter-element extension theory. The analytic hierarchy process (AHP), entropy weight and mean square variance (MSV) were used to determine the weights of light environment evaluation indexes, thus weakening the influence of subjective factors. The standard cloud matter-element model of light environment quality was constructed, and the degree of association between the evaluated matter-element and the standard cloud matter-element model was calculated. The light environment quality grade was determined by the information entropy theory. The confidence coefficient was defined by using theory of information entropy, which makes the reliability of evaluation results easy to calculate quantitatively. The validity and superiority of the model are verified by the practical example.