In order to evaluate POL (Petrol-Oil and Lubricants) support ability of naval vessel unit campaigning, evaluation indexes system is built from 6 aspects: the ability of POL storage, POL transportation, POL replenishment, response, organizing, repair and emergency disposal based on POL support characteristic and correlative demands of naval vessel unit campaigning. The cloud barycenter theory is adopted to build evaluation model of POL support ability of naval vessel unit campaigning, and the model is validated by analyzing an example. The result indicates that the method based on cloud barycenter theory can syncretize subjective and impersonal information effectively and solve the uncertainty transition between qualitative and quantitative problem in the evaluation, which reduces the impacts that fuzziness and randomness have in evaluation and improves the scientificity of POL support decision-making of naval vessel unit campaigning.