Currently, no offshore test field has been built for experiment, test and evaluation of tidal current energy generating device in China. The study of tidal current energy generation device performance integrated assessment method is an important part of the theoretical study for construction of an offshore test field, providing a reliable basis for improving the performance of tidal current energy generating device. On the basis of fuzzy comprehensive evaluation model using gray relational theory revision subjective weights, after analyzing performance indicators of tidal current energy generation device, the hierarchical model of device integrated assessment was given. By standardizing the indicators raw data, index values were in the (0,1), and the complexity of the calculations was reduced. Using the coefficient of variation and correlation corrected initial weight, a comprehensive weight value and the final assessment results of tidal current energy devices and more indicators were calculated. This method not only simplifies the process of standard AHP consistency test, but also avoids excessive subjective assessment results, improving the fuzzy comprehensive evaluation of credibility. The measured data of two units of tidal current energy generation devices were evaluated, and the effectiveness of the assessment methods was verified.