Abstract: Most organic coatings are subject to degradation and aging under light, salt fog, and temperature and humidity alternations, resulting in coating debonding or even peeling. Therefore, it is necessary to use non-destructive diagnosis techniques to detect the protectivity of the coating in real time, evaluate its aging degree, and provide guidelines for preventive maintenance of the coating. In addition, in order to improve the anti-aging performance of coatings, it is also necessary to clarify the failure mechanism of coatings and reveal the microdynamic process of coating aging as well as the relevant influencing factors. To this end, several coating aging evaluation methods were introduced, and the application of experimental methods and theoretical simulation in the study of coating aging mechanisms was described. Several coating life prediction models based on coating aging online monitoring technology, including acceleration factor methods, curve fitting methods, and life prediction methods such as life distribution models and neural network models based on big data analysis, were also introduced. At last, the deficiencies of the current research on coating aging and evaluation were summarized, and the important value of nondestructive coating monitoring technology in the accurate evaluation of coating life and maintenance cycle was looked forward.